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author | phil <phil@FreeBSD.org> | 2016-04-15 18:46:15 +0000 |
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committer | phil <phil@FreeBSD.org> | 2016-04-15 18:46:15 +0000 |
commit | ec6357ca208a98134a4c3a92b27cc6f8036a057f (patch) | |
tree | a8954be7f37694064eb0351a1cd9919c64c26cf8 /contrib/libxo/doc | |
parent | a723f9781d16f16c6f7af1cc7c6118663291ba0b (diff) | |
parent | f46a90ac38b5c37ca11e2f3abca36be64182ef03 (diff) | |
download | FreeBSD-src-ec6357ca208a98134a4c3a92b27cc6f8036a057f.zip FreeBSD-src-ec6357ca208a98134a4c3a92b27cc6f8036a057f.tar.gz |
Import to 0.6.1
0.5.0:
document "trim" modifier
add xo_emit_field functions
Add xo_set_file{,_h} functions
Fix LIBXO_* variables; add -L and -I as needed
add --disable-silent-rules and an explicit make; s/PACKAGE-NAME/PACKAGE_NAME/; add /download/ to 'url'
fix silliness where xo_flush_h emitted closing tag (html); make the caller (xo_message) do it
flush after transitions; fix flush call in xo_do_emit
mkdir the version-specific packaging dir
use "XO_" instead of LIBXO_
0.6.0:
Add --with-retain-size to set the size (in bits) of the retain hash buckets
Add The Argument Modifier ({a:})
Add retain and no-retain to --libxo
autoconf: Add test for monitor.h
Document quote heuristic
go deep with nroff backslashes
Use "ULL" for 32 bit check
add xo_retain_clear and xo_retain_clear_all
docs: combine two 'handles' section; move command line argument section
handle GETTEXT when msgfmt isn't where it's supposed to be (FreeBSD)
make 'retain' a flag (XOEF_RETAIN) instead of a role; it's simpler, and doesn't feel as tacky. "{R:}" was painful to document, which means it's painful to use.
new xo_emit_f functions
nuke some unused UNUSEDs
test code: path must be static
update test cases
0.6.1:
fix version number (missed a commit during new-release)
Reviewed by: sjg
Approved by: sjg (mentor)
Diffstat (limited to 'contrib/libxo/doc')
-rw-r--r-- | contrib/libxo/doc/libxo-manual.html | 1046 | ||||
-rw-r--r-- | contrib/libxo/doc/libxo.txt | 318 |
2 files changed, 810 insertions, 554 deletions
diff --git a/contrib/libxo/doc/libxo-manual.html b/contrib/libxo/doc/libxo-manual.html index 47881da..4db374b 100644 --- a/contrib/libxo/doc/libxo-manual.html +++ b/contrib/libxo/doc/libxo-manual.html @@ -515,7 +515,7 @@ li.indline1 { } @top-right { - content: "December 2015"; + content: "April 2016"; } @top-center { @@ -22009,7 +22009,7 @@ jQuery(function ($) { </tr> <tr> <td class="header left"></td> -<td class="header right">December 30, 2015</td> +<td class="header right">April 15, 2016</td> </tr> </table></div> <p id="title" class="title">libxo: The Easy Way to Generate text, XML, JSON, and HTML output<br><span class="filename">libxo-manual</span></p> @@ -22130,46 +22130,54 @@ jQuery(function ($) { <a href="#field-modifiers">Field Modifiers</a><ul class="toc"> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_1">2.2.2.1 </div> -<a href="#the-colon-modifier-c">The Colon Modifier ({c:})</a> +<a href="#the-argument-modifier-a">The Argument Modifier ({a:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_2">2.2.2.2 </div> -<a href="#the-display-modifier-d">The Display Modifier ({d:})</a> +<a href="#the-colon-modifier-c">The Colon Modifier ({c:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_3">2.2.2.3 </div> -<a href="#e-modifier">The Encoding Modifier ({e:})</a> +<a href="#the-display-modifier-d">The Display Modifier ({d:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_4">2.2.2.4 </div> -<a href="#gettext-modifier">The Gettext Modifier ({g:})</a> +<a href="#e-modifier">The Encoding Modifier ({e:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_5">2.2.2.5 </div> -<a href="#the-humanize-modifier-h">The Humanize Modifier ({h:})</a> +<a href="#gettext-modifier">The Gettext Modifier ({g:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_6">2.2.2.6 </div> -<a href="#the-key-modifier-k">The Key Modifier ({k:})</a> +<a href="#the-humanize-modifier-h">The Humanize Modifier ({h:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_7">2.2.2.7 </div> -<a href="#the-leaf-list-modifier-l">The Leaf-List Modifier ({l:})</a> +<a href="#the-key-modifier-k">The Key Modifier ({k:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_8">2.2.2.8 </div> -<a href="#the-no-quotes-modifier-n">The No-Quotes Modifier ({n:})</a> +<a href="#the-leaf-list-modifier-l">The Leaf-List Modifier ({l:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_9">2.2.2.9 </div> -<a href="#plural-modifier">The Plural Modifier ({p:})</a> +<a href="#the-no-quotes-modifier-n">The No-Quotes Modifier ({n:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_10">2.2.2.10 </div> -<a href="#the-quotes-modifier-q">The Quotes Modifier ({q:})</a> +<a href="#plural-modifier">The Plural Modifier ({p:})</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_2_11">2.2.2.11 </div> +<a href="#the-quotes-modifier-q">The Quotes Modifier ({q:})</a> +</li> +<li class="tocline1"> +<div class="section-number" id="toc_doc_section_2_2_2_12">2.2.2.12 </div> +<a href="#the-trim-modifier-t">The Trim Modifier ({t:})</a> +</li> +<li class="tocline1"> +<div class="section-number" id="toc_doc_section_2_2_2_13">2.2.2.13 </div> <a href="#the-white-space-modifier-w">The White Space Modifier ({w:})</a> </li> </ul> @@ -22208,42 +22216,38 @@ jQuery(function ($) { </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_2_11">2.2.11 </div> +<a href="#retain">Retaining Parsed Format Information</a> +</li> +<li class="tocline1"> +<div class="section-number" id="toc_doc_section_2_2_12">2.2.12 </div> <a href="#example">Example</a> </li> </ul> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_2_3">2.3 </div> -<a href="#command-line-arguments">Command-line Arguments</a> -</li> -<li class="tocline1"> -<div class="section-number" id="toc_doc_section_2_4">2.4 </div> <a href="#representing-hierarchy">Representing Hierarchy</a><ul class="toc"> <li class="tocline1"> -<div class="section-number" id="toc_doc_section_2_4_1">2.4.1 </div> +<div class="section-number" id="toc_doc_section_2_3_1">2.3.1 </div> <a href="#containers">Containers</a> </li> <li class="tocline1"> -<div class="section-number" id="toc_doc_section_2_4_2">2.4.2 </div> +<div class="section-number" id="toc_doc_section_2_3_2">2.3.2 </div> <a href="#lists-and-instances">Lists and Instances</a> </li> <li class="tocline1"> -<div class="section-number" id="toc_doc_section_2_4_3">2.4.3 </div> +<div class="section-number" id="toc_doc_section_2_3_3">2.3.3 </div> <a href="#dtrt-mode">DTRT Mode</a> </li> <li class="tocline1"> -<div class="section-number" id="toc_doc_section_2_4_4">2.4.4 </div> +<div class="section-number" id="toc_doc_section_2_3_4">2.3.4 </div> <a href="#markers">Markers</a> </li> </ul> </li> <li class="tocline1"> -<div class="section-number" id="toc_doc_section_2_5">2.5 </div> -<a href="#handles">Handles</a> -</li> -<li class="tocline1"> -<div class="section-number" id="toc_doc_section_2_6">2.6 </div> -<a href="#utf-8">UTF-8</a> +<div class="section-number" id="toc_doc_section_2_4">2.4 </div> +<a href="#command-line-arguments">Command-line Arguments</a> </li> </ul> </li> @@ -22252,7 +22256,7 @@ jQuery(function ($) { <a href="#the-libxo-api">The libxo API</a><ul class="toc top-toc"> <li class="tocline1"> <div class="section-number" id="toc_doc_section_3_1">3.1 </div> -<a href="#handles-2">Handles</a><ul class="toc"> +<a href="#handles">Handles</a><ul class="toc"> <li class="tocline1"> <div class="section-number" id="toc_doc_section_3_1_1">3.1.1 </div> <a href="#xo_create">xo_create</a> @@ -22306,14 +22310,18 @@ jQuery(function ($) { <a href="#emitting-content-xo_emit">Emitting Content (xo_emit)</a><ul class="toc"> <li class="tocline1"> <div class="section-number" id="toc_doc_section_3_2_1">3.2.1 </div> -<a href="#xo_attr">Attributes (xo_attr)</a> +<a href="#xo_emit_field">Single Field Emitting Functions (xo_emit_field)</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_3_2_2">3.2.2 </div> -<a href="#flushing-output-xo_flush">Flushing Output (xo_flush)</a> +<a href="#xo_attr">Attributes (xo_attr)</a> </li> <li class="tocline1"> <div class="section-number" id="toc_doc_section_3_2_3">3.2.3 </div> +<a href="#flushing-output-xo_flush">Flushing Output (xo_flush)</a> +</li> +<li class="tocline1"> +<div class="section-number" id="toc_doc_section_3_2_4">3.2.4 </div> <a href="#finishing-output-xo_finish">Finishing Output (xo_finish)</a> </li> </ul> @@ -22851,10 +22859,8 @@ jQuery(function ($) { <ul> <li><a href="#encoding-styles" title="Encoding Styles">Section 2.1</a></li> <li><a href="#format-strings" title="Format Strings">Section 2.2</a></li> -<li><a href="#command-line-arguments" title="Command-line Arguments">Section 2.3</a></li> -<li><a href="#representing-hierarchy" title="Representing Hierarchy">Section 2.4</a></li> -<li><a href="#handles" title="Handles">Section 2.5</a></li> -<li><a href="#utf-8" title="UTF-8">Section 2.6</a></li> +<li><a href="#representing-hierarchy" title="Representing Hierarchy">Section 2.3</a></li> +<li><a href="#command-line-arguments" title="Command-line Arguments">Section 2.4</a></li> </ul> <div class="content"> <h2 id="doc_section_2_1"> @@ -22992,7 +22998,8 @@ jQuery(function ($) { <li><a href="#the-encoding-format-eformat" title="The Encoding Format (eformat)">Section 2.2.8</a></li> <li><a href="#content-strings" title="Content Strings">Section 2.2.9</a></li> <li><a href="#printf-like" title="Argument Validation">Section 2.2.10</a></li> -<li><a href="#example" title="Example">Section 2.2.11</a></li> +<li><a href="#retain" title="Retaining Parsed Format Information">Section 2.2.11</a></li> +<li><a href="#example" title="Example">Section 2.2.12</a></li> </ul> <div class="content"> <h3 id="doc_section_2_2_1"> @@ -23356,6 +23363,11 @@ jQuery(function ($) { </tr></thead> <tbody> <tr> +<td>a</td> +<td>argument</td> +<td>The content appears as a 'const char *' argument</td> +</tr> +<tr> <td>c</td> <td>colon</td> <td>A colon (":") is appended after the label</td> @@ -23435,87 +23447,107 @@ jQuery(function ($) { <p id="doc_section_2_2_2_p_2">Roles and modifiers can also use more verbose names, when preceeded by a comma. For example, the modifier string "Lwc" (or "L,white,colon") means the field has a label role (text that describes the next field) and should be followed by a colon ('c') and a space ('w'). The modifier string "Vkq" (or ":key,quote") means the field has a value role (the default role), that it is a key for the current instance, and that the value should be quoted when encoded for JSON.</p> <p id="doc_section_2_2_2_p_3">Section Contents: </p> <ul> -<li><a href="#the-colon-modifier-c" title="The Colon Modifier ({c:})">Section 2.2.2.1</a></li> -<li><a href="#the-display-modifier-d" title="The Display Modifier ({d:})">Section 2.2.2.2</a></li> -<li><a href="#e-modifier" title="The Encoding Modifier ({e:})">Section 2.2.2.3</a></li> -<li><a href="#gettext-modifier" title="The Gettext Modifier ({g:})">Section 2.2.2.4</a></li> -<li><a href="#the-humanize-modifier-h" title="The Humanize Modifier ({h:})">Section 2.2.2.5</a></li> -<li><a href="#the-key-modifier-k" title="The Key Modifier ({k:})">Section 2.2.2.6</a></li> -<li><a href="#the-leaf-list-modifier-l" title="The Leaf-List Modifier ({l:})">Section 2.2.2.7</a></li> -<li><a href="#the-no-quotes-modifier-n" title="The No-Quotes Modifier ({n:})">Section 2.2.2.8</a></li> -<li><a href="#plural-modifier" title="The Plural Modifier ({p:})">Section 2.2.2.9</a></li> -<li><a href="#the-quotes-modifier-q" title="The Quotes Modifier ({q:})">Section 2.2.2.10</a></li> -<li><a href="#the-white-space-modifier-w" title="The White Space Modifier ({w:})">Section 2.2.2.11</a></li> +<li><a href="#the-argument-modifier-a" title="The Argument Modifier ({a:})">Section 2.2.2.1</a></li> +<li><a href="#the-colon-modifier-c" title="The Colon Modifier ({c:})">Section 2.2.2.2</a></li> +<li><a href="#the-display-modifier-d" title="The Display Modifier ({d:})">Section 2.2.2.3</a></li> +<li><a href="#e-modifier" title="The Encoding Modifier ({e:})">Section 2.2.2.4</a></li> +<li><a href="#gettext-modifier" title="The Gettext Modifier ({g:})">Section 2.2.2.5</a></li> +<li><a href="#the-humanize-modifier-h" title="The Humanize Modifier ({h:})">Section 2.2.2.6</a></li> +<li><a href="#the-key-modifier-k" title="The Key Modifier ({k:})">Section 2.2.2.7</a></li> +<li><a href="#the-leaf-list-modifier-l" title="The Leaf-List Modifier ({l:})">Section 2.2.2.8</a></li> +<li><a href="#the-no-quotes-modifier-n" title="The No-Quotes Modifier ({n:})">Section 2.2.2.9</a></li> +<li><a href="#plural-modifier" title="The Plural Modifier ({p:})">Section 2.2.2.10</a></li> +<li><a href="#the-quotes-modifier-q" title="The Quotes Modifier ({q:})">Section 2.2.2.11</a></li> +<li><a href="#the-trim-modifier-t" title="The Trim Modifier ({t:})">Section 2.2.2.12</a></li> +<li><a href="#the-white-space-modifier-w" title="The White Space Modifier ({w:})">Section 2.2.2.13</a></li> </ul> <div class="content"> <h4 id="doc_section_2_2_2_1"> <div class="self-section-number"> <a href="#doc_section_2_2_2_1">2.2.2.1</a> </div> -<a id="the-colon-modifier-c" href="#the-colon-modifier-c">The Colon Modifier ({c:})</a> +<a id="the-argument-modifier-a" href="#the-argument-modifier-a">The Argument Modifier ({a:})</a> </h4> -<p id="doc_section_2_2_2_1_p_1">The colon modifier appends a single colon to the data value:</p> +<p id="doc_section_2_2_2_1_p_1">The argument modifier indicates that the content of the field descriptor will be placed as a UTF-8 string (const char *) argument within the xo_emit parameters.</p> <div id="doc_figure_u.48"></div> <pre> EXAMPLE: - xo_emit("{Lc:Name}{:name}\n", "phil"); + xo_emit("{La:} {a:}\n", "Label text", "label", "value"); TEXT: - Name:phil - </pre> <p id="doc_section_2_2_2_1_p_3">The colon modifier is only used for the TEXT and HTML output styles. It is commonly combined with the space modifier ('{w:}'). It is purely a convenience feature.</p> + Label text value + JSON: + "label": "value" + XML: + <label>value</label> + </pre> <p id="doc_section_2_2_2_1_p_3">The argument modifier allows field names for value fields to be passed on the stack, avoiding the need to build a field descriptor using snprintf. For many field roles, the argument modifier is not needed, since those roles have specific mechanisms for arguments, such as "{C:fg‑%s}".</p> </div> <div class="content"> <h4 id="doc_section_2_2_2_2"> <div class="self-section-number"> <a href="#doc_section_2_2_2_2">2.2.2.2</a> </div> -<a id="the-display-modifier-d" href="#the-display-modifier-d">The Display Modifier ({d:})</a> +<a id="the-colon-modifier-c" href="#the-colon-modifier-c">The Colon Modifier ({c:})</a> </h4> -<p id="doc_section_2_2_2_2_p_1">The display modifier indicated the field should only be generated for the display output styles, TEXT and HTML.</p> +<p id="doc_section_2_2_2_2_p_1">The colon modifier appends a single colon to the data value:</p> <div id="doc_figure_u.49"></div> <pre> EXAMPLE: + xo_emit("{Lc:Name}{:name}\n", "phil"); + TEXT: + Name:phil + </pre> <p id="doc_section_2_2_2_2_p_3">The colon modifier is only used for the TEXT and HTML output styles. It is commonly combined with the space modifier ('{w:}'). It is purely a convenience feature.</p> +</div> +<div class="content"> +<h4 id="doc_section_2_2_2_3"> +<div class="self-section-number"> +<a href="#doc_section_2_2_2_3">2.2.2.3</a> </div> +<a id="the-display-modifier-d" href="#the-display-modifier-d">The Display Modifier ({d:})</a> +</h4> +<p id="doc_section_2_2_2_3_p_1">The display modifier indicated the field should only be generated for the display output styles, TEXT and HTML.</p> +<div id="doc_figure_u.50"></div> <pre> + EXAMPLE: xo_emit("{Lcw:Name}{d:name} {:id/%d}\n", "phil", 1); TEXT: Name: phil 1 XML: <id>1</id> - </pre> <p id="doc_section_2_2_2_2_p_3">The display modifier is the opposite of the encoding modifier, and they are often used to give to distinct views of the underlying data.</p> + </pre> <p id="doc_section_2_2_2_3_p_3">The display modifier is the opposite of the encoding modifier, and they are often used to give to distinct views of the underlying data.</p> </div> <div class="content"> -<h4 id="doc_section_2_2_2_3"> +<h4 id="doc_section_2_2_2_4"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_3">2.2.2.3</a> </div> +<a href="#doc_section_2_2_2_4">2.2.2.4</a> </div> <a id="e-modifier" href="#e-modifier">The Encoding Modifier ({e:})</a> </h4> -<p id="doc_section_2_2_2_3_p_1">The display modifier indicated the field should only be generated for the display output styles, TEXT and HTML.</p> -<div id="doc_figure_u.50"></div> <pre> +<p id="doc_section_2_2_2_4_p_1">The display modifier indicated the field should only be generated for the display output styles, TEXT and HTML.</p> +<div id="doc_figure_u.51"></div> <pre> EXAMPLE: xo_emit("{Lcw:Name}{:name} {e:id/%d}\n", "phil", 1); TEXT: Name: phil XML: <name>phil</name><id>1</id> - </pre> <p id="doc_section_2_2_2_3_p_3">The encoding modifier is the opposite of the display modifier, and they are often used to give to distinct views of the underlying data.</p> + </pre> <p id="doc_section_2_2_2_4_p_3">The encoding modifier is the opposite of the display modifier, and they are often used to give to distinct views of the underlying data.</p> </div> <div class="content"> -<h4 id="doc_section_2_2_2_4"> +<h4 id="doc_section_2_2_2_5"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_4">2.2.2.4</a> </div> +<a href="#doc_section_2_2_2_5">2.2.2.5</a> </div> <a id="gettext-modifier" href="#gettext-modifier">The Gettext Modifier ({g:})</a> </h4> -<p id="doc_section_2_2_2_4_p_1">The gettext modifier is used to translate individual fields using the gettext domain (typically set using the "{G:}" role) and current language settings. Once libxo renders the field value, it is passed to gettext(3), where it is used as a key to find the native language translation.</p> -<p id="doc_section_2_2_2_4_p_2">In the following example, the strings "State" and "full" are passed to gettext() to find locale-based translated strings.</p> -<div id="doc_figure_u.51"></div> <pre> +<p id="doc_section_2_2_2_5_p_1">The gettext modifier is used to translate individual fields using the gettext domain (typically set using the "{G:}" role) and current language settings. Once libxo renders the field value, it is passed to gettext(3), where it is used as a key to find the native language translation.</p> +<p id="doc_section_2_2_2_5_p_2">In the following example, the strings "State" and "full" are passed to gettext() to find locale-based translated strings.</p> +<div id="doc_figure_u.52"></div> <pre> xo_emit("{Lgwc:State}{g:state}\n", "full"); - </pre> <p id="doc_section_2_2_2_4_p_4">See <a href="#gettext-role" title="The Gettext Role ({G:})">Section 2.2.1.3</a>, <a href="#plural-modifier" title="The Plural Modifier ({p:})">Section 2.2.2.9</a>, and <a href="#howto-i18n" title="Howto: Internationalization (i18n)">Section 9.5</a> for additional details.</p> + </pre> <p id="doc_section_2_2_2_5_p_4">See <a href="#gettext-role" title="The Gettext Role ({G:})">Section 2.2.1.3</a>, <a href="#plural-modifier" title="The Plural Modifier ({p:})">Section 2.2.2.10</a>, and <a href="#howto-i18n" title="Howto: Internationalization (i18n)">Section 9.5</a> for additional details.</p> </div> <div class="content"> -<h4 id="doc_section_2_2_2_5"> +<h4 id="doc_section_2_2_2_6"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_5">2.2.2.5</a> </div> +<a href="#doc_section_2_2_2_6">2.2.2.6</a> </div> <a id="the-humanize-modifier-h" href="#the-humanize-modifier-h">The Humanize Modifier ({h:})</a> </h4> -<p id="doc_section_2_2_2_5_p_1">The humanize modifier is used to render large numbers as in a human-readable format. While numbers like "44470272" are completely readable to computers and savants, humans will generally find "44M" more meaningful.</p> -<p id="doc_section_2_2_2_5_p_2">"hn" can be used as an alias for "humanize".</p> -<p id="doc_section_2_2_2_5_p_3">The humanize modifier only affects display styles (TEXT and HMTL). The "no‑humanize" option (See <a href="#LIBXO_OPTIONS" title="LIBXO_OPTIONS">Section 3.4.6</a>) will block the function of the humanize modifier.</p> -<p id="doc_section_2_2_2_5_p_4">There are a number of modifiers that affect details of humanization. These are only available in as full names, not single characters. The "hn‑space" modifier places a space between the number and any multiplier symbol, such as "M" or "K" (ex: "44 K"). The "hn‑decimal" modifier will add a decimal point and a single tenths digit when the number is less than 10 (ex: "4.4K"). The "hn‑1000" modifier will use 1000 as divisor instead of 1024, following the JEDEC-standard instead of the more natural binary powers-of-two tradition.</p> -<div id="doc_figure_u.52"></div> <pre> +<p id="doc_section_2_2_2_6_p_1">The humanize modifier is used to render large numbers as in a human-readable format. While numbers like "44470272" are completely readable to computers and savants, humans will generally find "44M" more meaningful.</p> +<p id="doc_section_2_2_2_6_p_2">"hn" can be used as an alias for "humanize".</p> +<p id="doc_section_2_2_2_6_p_3">The humanize modifier only affects display styles (TEXT and HMTL). The "no‑humanize" option (See <a href="#LIBXO_OPTIONS" title="LIBXO_OPTIONS">Section 3.4.6</a>) will block the function of the humanize modifier.</p> +<p id="doc_section_2_2_2_6_p_4">There are a number of modifiers that affect details of humanization. These are only available in as full names, not single characters. The "hn‑space" modifier places a space between the number and any multiplier symbol, such as "M" or "K" (ex: "44 K"). The "hn‑decimal" modifier will add a decimal point and a single tenths digit when the number is less than 10 (ex: "4.4K"). The "hn‑1000" modifier will use 1000 as divisor instead of 1024, following the JEDEC-standard instead of the more natural binary powers-of-two tradition.</p> +<div id="doc_figure_u.53"></div> <pre> EXAMPLE: xo_emit("{h:input/%u}, {h,hn-space:output/%u}, " "{h,hn-decimal:errors/%u}, {h,hn-1000:capacity/%u}, " @@ -23523,19 +23555,19 @@ jQuery(function ($) { input, output, errors, capacity, remaining); TEXT: 21, 57 K, 96M, 44M, 1.2G - </pre> <p id="doc_section_2_2_2_5_p_6">In the HTML style, the original numeric value is rendered in the "data‑number" attribute on the <div> element:</p> -<div id="doc_figure_u.53"></div> <pre> + </pre> <p id="doc_section_2_2_2_6_p_6">In the HTML style, the original numeric value is rendered in the "data‑number" attribute on the <div> element:</p> +<div id="doc_figure_u.54"></div> <pre> <div class="data" data-tag="errors" data-number="100663296">96M</div> </pre> </div> <div class="content"> -<h4 id="doc_section_2_2_2_6"> +<h4 id="doc_section_2_2_2_7"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_6">2.2.2.6</a> </div> +<a href="#doc_section_2_2_2_7">2.2.2.7</a> </div> <a id="the-key-modifier-k" href="#the-key-modifier-k">The Key Modifier ({k:})</a> </h4> -<p id="doc_section_2_2_2_6_p_1">The key modifier is used to indicate that a particular field helps uniquely identify an instance of list data.</p> -<div id="doc_figure_u.54"></div> <pre> +<p id="doc_section_2_2_2_7_p_1">The key modifier is used to indicate that a particular field helps uniquely identify an instance of list data.</p> +<div id="doc_figure_u.55"></div> <pre> EXAMPLE: xo_open_list("user"); for (i = 0; i < num_users; i++) { @@ -23545,16 +23577,16 @@ jQuery(function ($) { xo_close_instance("user"); } xo_close_list("user"); - </pre> <p id="doc_section_2_2_2_6_p_3">Currently the key modifier is only used when generating XPath value for the HTML output style when XOF_XPATH is set, but other uses are likely in the near future.</p> + </pre> <p id="doc_section_2_2_2_7_p_3">Currently the key modifier is only used when generating XPath value for the HTML output style when XOF_XPATH is set, but other uses are likely in the near future.</p> </div> <div class="content"> -<h4 id="doc_section_2_2_2_7"> +<h4 id="doc_section_2_2_2_8"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_7">2.2.2.7</a> </div> +<a href="#doc_section_2_2_2_8">2.2.2.8</a> </div> <a id="the-leaf-list-modifier-l" href="#the-leaf-list-modifier-l">The Leaf-List Modifier ({l:})</a> </h4> -<p id="doc_section_2_2_2_7_p_1">The leaf-list modifier is used to distinguish lists where each instance consists of only a single value. In XML, these are rendered as single elements, where JSON renders them as arrays.</p> -<div id="doc_figure_u.55"></div> <pre> +<p id="doc_section_2_2_2_8_p_1">The leaf-list modifier is used to distinguish lists where each instance consists of only a single value. In XML, these are rendered as single elements, where JSON renders them as arrays.</p> +<div id="doc_figure_u.56"></div> <pre> EXAMPLE: for (i = 0; i < num_users; i++) { xo_emit("Member {l:user}\n", user[i].u_name); @@ -23564,16 +23596,16 @@ jQuery(function ($) { <user>pallavi</user> JSON: "user": [ "phil", "pallavi" ] - </pre> <p id="doc_section_2_2_2_7_p_3">The name of the field must match the name of the leaf list.</p> + </pre> <p id="doc_section_2_2_2_8_p_3">The name of the field must match the name of the leaf list.</p> </div> <div class="content"> -<h4 id="doc_section_2_2_2_8"> +<h4 id="doc_section_2_2_2_9"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_8">2.2.2.8</a> </div> +<a href="#doc_section_2_2_2_9">2.2.2.9</a> </div> <a id="the-no-quotes-modifier-n" href="#the-no-quotes-modifier-n">The No-Quotes Modifier ({n:})</a> </h4> -<p id="doc_section_2_2_2_8_p_1">The no-quotes modifier (and its twin, the 'quotes' modifier) affect the quoting of values in the JSON output style. JSON uses quotes for string value, but no quotes for numeric, boolean, and null data. xo_emit applies a simple heuristic to determine whether quotes are needed, but often this needs to be controlled by the caller.</p> -<div id="doc_figure_u.56"></div> <pre> +<p id="doc_section_2_2_2_9_p_1">The no-quotes modifier (and its twin, the 'quotes' modifier) affect the quoting of values in the JSON output style. JSON uses quotes for string value, but no quotes for numeric, boolean, and null data. xo_emit applies a simple heuristic to determine whether quotes are needed, but often this needs to be controlled by the caller.</p> +<div id="doc_figure_u.57"></div> <pre> EXAMPLE: const char *bool = is_true ? "true" : "false"; xo_emit("{n:fancy/%s}", bool); @@ -23581,45 +23613,61 @@ jQuery(function ($) { "fancy": true </pre> </div> <div class="content"> -<h4 id="doc_section_2_2_2_9"> +<h4 id="doc_section_2_2_2_10"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_9">2.2.2.9</a> </div> +<a href="#doc_section_2_2_2_10">2.2.2.10</a> </div> <a id="plural-modifier" href="#plural-modifier">The Plural Modifier ({p:})</a> </h4> -<p id="doc_section_2_2_2_9_p_1">The plural modifier selects the appropriate plural form of an expression based on the most recent number emitted and the current language settings. The contents of the field should be the singular and plural English values, separated by a comma:</p> -<div id="doc_figure_u.57"></div> <pre> +<p id="doc_section_2_2_2_10_p_1">The plural modifier selects the appropriate plural form of an expression based on the most recent number emitted and the current language settings. The contents of the field should be the singular and plural English values, separated by a comma:</p> +<div id="doc_figure_u.58"></div> <pre> xo_emit("{:bytes} {Ngp:byte,bytes}\n", bytes); - </pre> <p id="doc_section_2_2_2_9_p_3">The plural modifier is meant to work with the gettext modifier ({g:}) but can work independently. See <a href="#gettext-modifier" title="The Gettext Modifier ({g:})">Section 2.2.2.4</a>.</p> -<p id="doc_section_2_2_2_9_p_4">When used without the gettext modifier or when the message does not appear in the message catalog, the first token is chosen when the last numeric value is equal to 1; otherwise the second value is used, mimicking the simple pluralization rules of English.</p> -<p id="doc_section_2_2_2_9_p_5">When used with the gettext modifier, the ngettext(3) function is called to handle the heavy lifting, using the message catalog to convert the singular and plural forms into the native language.</p> + </pre> <p id="doc_section_2_2_2_10_p_3">The plural modifier is meant to work with the gettext modifier ({g:}) but can work independently. See <a href="#gettext-modifier" title="The Gettext Modifier ({g:})">Section 2.2.2.5</a>.</p> +<p id="doc_section_2_2_2_10_p_4">When used without the gettext modifier or when the message does not appear in the message catalog, the first token is chosen when the last numeric value is equal to 1; otherwise the second value is used, mimicking the simple pluralization rules of English.</p> +<p id="doc_section_2_2_2_10_p_5">When used with the gettext modifier, the ngettext(3) function is called to handle the heavy lifting, using the message catalog to convert the singular and plural forms into the native language.</p> </div> <div class="content"> -<h4 id="doc_section_2_2_2_10"> +<h4 id="doc_section_2_2_2_11"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_10">2.2.2.10</a> </div> +<a href="#doc_section_2_2_2_11">2.2.2.11</a> </div> <a id="the-quotes-modifier-q" href="#the-quotes-modifier-q">The Quotes Modifier ({q:})</a> </h4> -<p id="doc_section_2_2_2_10_p_1">The quotes modifier (and its twin, the 'no‑quotes' modifier) affect the quoting of values in the JSON output style. JSON uses quotes for string value, but no quotes for numeric, boolean, and null data. xo_emit applies a simple heuristic to determine whether quotes are needed, but often this needs to be controlled by the caller.</p> -<div id="doc_figure_u.58"></div> <pre> +<p id="doc_section_2_2_2_11_p_1">The quotes modifier (and its twin, the 'no‑quotes' modifier) affect the quoting of values in the JSON output style. JSON uses quotes for string value, but no quotes for numeric, boolean, and null data. xo_emit applies a simple heuristic to determine whether quotes are needed, but often this needs to be controlled by the caller.</p> +<div id="doc_figure_u.59"></div> <pre> EXAMPLE: xo_emit("{q:time/%d}", 2014); JSON: "year": "2014" + </pre> <p id="doc_section_2_2_2_11_p_3">The heuristic is based on the format; if the format uses any of the following conversion specifiers, then no quotes are used:</p> +<div id="doc_figure_u.60"></div> <pre> + d i o u x X D O U e E f F g G a A c C p </pre> </div> <div class="content"> -<h4 id="doc_section_2_2_2_11"> +<h4 id="doc_section_2_2_2_12"> <div class="self-section-number"> -<a href="#doc_section_2_2_2_11">2.2.2.11</a> </div> +<a href="#doc_section_2_2_2_12">2.2.2.12</a> </div> +<a id="the-trim-modifier-t" href="#the-trim-modifier-t">The Trim Modifier ({t:})</a> +</h4> +<p id="doc_section_2_2_2_12_p_1">The trim modifier removes any leading or trailing whitespace from the value.</p> +<div id="doc_figure_u.61"></div> <pre> + EXAMPLE: + xo_emit("{t:description}", " some input "); + JSON: + "description": "some input" + </pre> </div> +<div class="content"> +<h4 id="doc_section_2_2_2_13"> +<div class="self-section-number"> +<a href="#doc_section_2_2_2_13">2.2.2.13</a> </div> <a id="the-white-space-modifier-w" href="#the-white-space-modifier-w">The White Space Modifier ({w:})</a> </h4> -<p id="doc_section_2_2_2_11_p_1">The white space modifier appends a single space to the data value:</p> -<div id="doc_figure_u.59"></div> <pre> +<p id="doc_section_2_2_2_13_p_1">The white space modifier appends a single space to the data value:</p> +<div id="doc_figure_u.62"></div> <pre> EXAMPLE: xo_emit("{Lw:Name}{:name}\n", "phil"); TEXT: Name phil - </pre> <p id="doc_section_2_2_2_11_p_3">The white space modifier is only used for the TEXT and HTML output styles. It is commonly combined with the colon modifier ('{c:}'). It is purely a convenience feature.</p> -<p id="doc_section_2_2_2_11_p_4">Note that the sense of the 'w' modifier is reversed for the units role ({Uw:}); a blank is added before the contents, rather than after it.</p> + </pre> <p id="doc_section_2_2_2_13_p_3">The white space modifier is only used for the TEXT and HTML output styles. It is commonly combined with the colon modifier ('{c:}'). It is purely a convenience feature.</p> +<p id="doc_section_2_2_2_13_p_4">Note that the sense of the 'w' modifier is reversed for the units role ({Uw:}); a blank is added before the contents, rather than after it.</p> </div> </div> <div class="content"> @@ -23632,7 +23680,7 @@ jQuery(function ($) { <p id="doc_section_2_2_3_p_2">If the format string is not provided for a value field, it defaults to "%s".</p> <p id="doc_section_2_2_3_p_3">Note a field definition can contain zero or more printf-style 'directives', which are sequences that start with a '%' and end with one of following characters: "diouxXDOUeEfFgGaAcCsSp". Each directive is matched by one of more arguments to the xo_emit function.</p> <p id="doc_section_2_2_3_p_4">The format string has the form:</p> -<div id="doc_figure_u.60"></div> <pre> +<div id="doc_figure_u.63"></div> <pre> '%' format-modifier * format-character </pre> <p id="doc_section_2_2_3_p_6">The format- modifier can be:</p> <p id="doc_section_2_2_3_p_7"> </p> @@ -23829,8 +23877,42 @@ jQuery(function ($) { <a id="utf-8-and-locale-strings" href="#utf-8-and-locale-strings">UTF-8 and Locale Strings</a> </h3> <p id="doc_section_2_2_4_p_1">For strings, the 'h' and 'l' modifiers affect the interpretation of the bytes pointed to argument. The default '%s' string is a 'char *' pointer to a string encoded as UTF-8. Since UTF-8 is compatible with ASCII data, a normal 7-bit ASCII string can be used. '%ls' expects a 'wchar_t *' pointer to a wide-character string, encoded as a 32-bit Unicode values. '%hs' expects a 'char *' pointer to a multi-byte string encoded with the current locale, as given by the LC_CTYPE, LANG, or LC_ALL environment varibles. The first of this list of variables is used and if none of the variables are set, the locale defaults to "UTF‑8".</p> -<p id="doc_section_2_2_4_p_2">For example, a function is passed a locale-base name, a hat size, and a time value. The hat size is formatted in a UTF-8 (ASCII) string, and the time value is formatted into a wchar_t string.</p> -<div id="doc_figure_u.61"></div> <pre> +<p id="doc_section_2_2_4_p_2">libxo will convert these arguments as needed to either UTF-8 (for XML, JSON, and HTML styles) or locale-based strings for display in text style.</p> +<div id="doc_figure_u.64"></div> <pre> + xo_emit("Alll strings are utf-8 content {:tag/%ls}", + L"except for wide strings"); + </pre> <p id="doc_section_2_2_4_p_4">"%S" is equivalent to "%ls".</p> +<div id="doc_table_u.7"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<thead><tr> +<th class="left">Format</th> +<th class="left">Argument Type</th> +<th class="left">Argument Contents</th> +</tr></thead> +<tbody> +<tr> +<td>%s</td> +<td>const char *</td> +<td>UTF-8 string</td> +</tr> +<tr> +<td>%S</td> +<td>const char *</td> +<td>UTF-8 string (alias for '%s')</td> +</tr> +<tr> +<td>%ls</td> +<td>const wchar_t *</td> +<td>Wide character UNICODE string</td> +</tr> +<tr> +<td>%hs</td> +<td>const char *</td> +<td>locale-based string</td> +</tr> +</tbody> +</table></div> +<p id="doc_section_2_2_4_p_5">For example, a function is passed a locale-base name, a hat size, and a time value. The hat size is formatted in a UTF-8 (ASCII) string, and the time value is formatted into a wchar_t string.</p> +<div id="doc_figure_u.65"></div> <pre> void print_order (const char *name, int size, struct tm *timep) { char buf[32]; @@ -23849,10 +23931,10 @@ jQuery(function ($) { xo_emit("It was ordered on {:order-time/%ls}.\n", when); } - </pre> <p id="doc_section_2_2_4_p_4">It is important to note that xo_emit will perform the conversion required to make appropriate output. Text style output uses the current locale (as described above), while XML, JSON, and HTML use UTF-8.</p> -<p id="doc_section_2_2_4_p_5">UTF-8 and locale-encoded strings can use multiple bytes to encode one column of data. The traditional "precision'" (aka "max‑width") value for "%s" printf formatting becomes overloaded since it specifies both the number of bytes that can be safely referenced and the maximum number of columns to emit. xo_emit uses the precision as the former, and adds a third value for specifying the maximum number of columns.</p> -<p id="doc_section_2_2_4_p_6">In this example, the name field is printed with a minimum of 3 columns and a maximum of 6. Up to ten bytes of data at the location given by 'name' are in used in filling those columns.</p> -<div id="doc_figure_u.62"></div> <pre> + </pre> <p id="doc_section_2_2_4_p_7">It is important to note that xo_emit will perform the conversion required to make appropriate output. Text style output uses the current locale (as described above), while XML, JSON, and HTML use UTF-8.</p> +<p id="doc_section_2_2_4_p_8">UTF-8 and locale-encoded strings can use multiple bytes to encode one column of data. The traditional "precision'" (aka "max‑width") value for "%s" printf formatting becomes overloaded since it specifies both the number of bytes that can be safely referenced and the maximum number of columns to emit. xo_emit uses the precision as the former, and adds a third value for specifying the maximum number of columns.</p> +<p id="doc_section_2_2_4_p_9">In this example, the name field is printed with a minimum of 3 columns and a maximum of 6. Up to ten bytes of data at the location given by 'name' are in used in filling those columns.</p> +<div id="doc_figure_u.66"></div> <pre> xo_emit("{:name/%3.10.6s}", name); </pre> </div> <div class="content"> @@ -23862,7 +23944,7 @@ jQuery(function ($) { <a id="characters-outside-of-field-definitions" href="#characters-outside-of-field-definitions">Characters Outside of Field Definitions</a> </h3> <p id="doc_section_2_2_5_p_1">Characters in the format string that are not part of a field definition are copied to the output for the TEXT style, and are ignored for the JSON and XML styles. For HTML, these characters are placed in a <div> with class "text".</p> -<div id="doc_figure_u.63"></div> <pre> +<div id="doc_figure_u.67"></div> <pre> EXAMPLE: xo_emit("The hat is {:size/%s}.\n", size_val); TEXT: @@ -23883,7 +23965,7 @@ jQuery(function ($) { <a id="m-is-supported" href="#m-is-supported">"%m" Is Supported</a> </h3> <p id="doc_section_2_2_6_p_1">libxo supports the '%m' directive, which formats the error message associated with the current value of "errno". It is the equivalent of "%s" with the argument strerror(errno).</p> -<div id="doc_figure_u.64"></div> <pre> +<div id="doc_figure_u.68"></div> <pre> xo_emit("{:filename} cannot be opened: {:error/%m}", filename); xo_emit("{:filename} cannot be opened: {:error/%s}", filename, strerror(errno)); @@ -23930,7 +24012,7 @@ jQuery(function ($) { <li>distinct encoding formats, where "{:tag/#%s/%s}" means the display styles (text and HTML) will use "#%s" where other styles use "%s";</li> </ul> <p id="doc_section_2_2_10_p_5">If none of these features are in use by your code, then using the "_p" variants might be wise.</p> -<div id="doc_table_u.7"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.8"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Function</th> <th class="left">printf-like Equivalent</th> @@ -23987,14 +24069,71 @@ jQuery(function ($) { <h3 id="doc_section_2_2_11"> <div class="self-section-number"> <a href="#doc_section_2_2_11">2.2.11</a> </div> +<a id="retain" href="#retain">Retaining Parsed Format Information</a> +</h3> +<p id="doc_section_2_2_11_p_1">libxo can retain the parsed internal information related to the given format string, allowing subsequent xo_emit calls, the retained information is used, avoiding repetitive parsing of the format string.</p> +<div id="doc_figure_u.69"></div> <pre> + SYNTAX: + int xo_emit_f(xo_emit_flags_t flags, const char fmt, ...); + EXAMPLE: + xo_emit_f(XOEF_RETAIN, "{:some/%02d}{:thing/%-6s}{:fancy}\n", + some, thing, fancy); + </pre> <p id="doc_section_2_2_11_p_3">To retain parsed format information, use the XOEF_RETAIN flag to the xo_emit_f() function. A complete set of xo_emit_f functions exist to match all the xo_emit function signatures (with handles, varadic argument, and printf-like flags):</p> +<div id="doc_table_u.9"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<thead><tr> +<th class="left">Function</th> +<th class="left">Flags Equivalent</th> +</tr></thead> +<tbody> +<tr> +<td>xo_emit_hv</td> +<td>xo_emit_hvf</td> +</tr> +<tr> +<td>xo_emit_h</td> +<td>xo_emit_hf</td> +</tr> +<tr> +<td>xo_emit</td> +<td>xo_emit_f</td> +</tr> +<tr> +<td>xo_emit_hvp</td> +<td>xo_emit_hvfp</td> +</tr> +<tr> +<td>xo_emit_hp</td> +<td>xo_emit_hfp</td> +</tr> +<tr> +<td>xo_emit_p</td> +<td>xo_emit_fp</td> +</tr> +</tbody> +</table></div> +<p id="doc_section_2_2_11_p_4">The format string must be immutable across multiple calls to xo_emit_f(), since the library retains the string. Typically this is done by using static constant strings, such as string literals. If the string is not immutable, the XOEF_RETAIN flag must not be used.</p> +<p id="doc_section_2_2_11_p_5">The functions xo_retain_clear() and xo_retain_clear_all() release internal information on either a single format string or all format strings, respectively. Neither is required, but the library will retain this information until it is cleared or the process exits.</p> +<div id="doc_figure_u.70"></div> <pre> + const char *fmt = "{:name} {:count/%d}\n"; + for (i = 0; i < 1000; i++) { + xo_open_instance("item"); + xo_emit_f(XOEF_RETAIN, fmt, name[i], count[i]); + } + xo_retain_clear(fmt); + </pre> <p id="doc_section_2_2_11_p_7">The retained information is kept as thread-specific data.</p> +</div> +<div class="content"> +<h3 id="doc_section_2_2_12"> +<div class="self-section-number"> +<a href="#doc_section_2_2_12">2.2.12</a> </div> <a id="example" href="#example">Example</a> </h3> -<p id="doc_section_2_2_11_p_1">In this example, the value for the number of items in stock is emitted:</p> -<div id="doc_figure_u.65"></div> <pre> +<p id="doc_section_2_2_12_p_1">In this example, the value for the number of items in stock is emitted:</p> +<div id="doc_figure_u.71"></div> <pre> xo_emit("{P: }{Lwc:In stock}{:in-stock/%u}\n", instock); - </pre> <p id="doc_section_2_2_11_p_3">This call will generate the following output:</p> -<div id="doc_figure_u.66"></div> <pre> + </pre> <p id="doc_section_2_2_12_p_3">This call will generate the following output:</p> +<div id="doc_figure_u.72"></div> <pre> TEXT: In stock: 144 XML: @@ -24009,8 +24148,8 @@ jQuery(function ($) { <div class="padding"> </div> <div class="data" data-tag="in-stock">144</div> </div> - </pre> <p id="doc_section_2_2_11_p_5">Clearly HTML wins the verbosity award, and this output does not include XOF_XPATH or XOF_INFO data, which would expand the penultimate line to:</p> -<div id="doc_figure_u.67"></div> <pre> + </pre> <p id="doc_section_2_2_12_p_5">Clearly HTML wins the verbosity award, and this output does not include XOF_XPATH or XOF_INFO data, which would expand the penultimate line to:</p> +<div id="doc_figure_u.73"></div> <pre> <div class="data" data-tag="in-stock" data-xpath="/top/data/item/in-stock" data-type="number" @@ -24021,17 +24160,148 @@ jQuery(function ($) { <h2 id="doc_section_2_3"> <div class="self-section-number"> <a href="#doc_section_2_3">2.3</a> </div> +<a id="representing-hierarchy" href="#representing-hierarchy">Representing Hierarchy</a> +</h2> +<p id="doc_section_2_3_p_1">For XML and JSON, individual fields appear inside hierarchies which provide context and meaning to the fields. Unfortunately, these encoding have a basic disconnect between how lists is similar objects are represented.</p> +<p id="doc_section_2_3_p_2">XML encodes lists as set of sequential elements:</p> +<div id="doc_figure_u.74"></div> <pre> + <user>phil</user> + <user>pallavi</user> + <user>sjg</user> + </pre> <p id="doc_section_2_3_p_4">JSON encodes lists using a single name and square brackets:</p> +<div id="doc_figure_u.75"></div> <pre> + "user": [ "phil", "pallavi", "sjg" ] + </pre> <p id="doc_section_2_3_p_6">This means libxo needs three distinct indications of hierarchy: one for containers of hierarchy appear only once for any specific parent, one for lists, and one for each item in a list.</p> +<p id="doc_section_2_3_p_7">Section Contents: </p> +<ul> +<li><a href="#containers" title="Containers">Section 2.3.1</a></li> +<li><a href="#lists-and-instances" title="Lists and Instances">Section 2.3.2</a></li> +<li><a href="#dtrt-mode" title="DTRT Mode">Section 2.3.3</a></li> +<li><a href="#markers" title="Markers">Section 2.3.4</a></li> +</ul> +<div class="content"> +<h3 id="doc_section_2_3_1"> +<div class="self-section-number"> +<a href="#doc_section_2_3_1">2.3.1</a> </div> +<a id="containers" href="#containers">Containers</a> +</h3> +<p id="doc_section_2_3_1_p_1">A "container" is an element of a hierarchy that appears only once under any specific parent. The container has no value, but serves to contain other nodes.</p> +<p id="doc_section_2_3_1_p_2">To open a container, call xo_open_container() or xo_open_container_h(). The former uses the default handle and the latter accepts a specific handle.</p> +<div id="doc_figure_u.76"></div> <pre> + int xo_open_container_h (xo_handle_t *xop, const char *name); + int xo_open_container (const char *name); + </pre> <p id="doc_section_2_3_1_p_4">To close a level, use the xo_close_container() or xo_close_container_h() functions:</p> +<div id="doc_figure_u.77"></div> <pre> + int xo_close_container_h (xo_handle_t *xop, const char *name); + int xo_close_container (const char *name); + </pre> <p id="doc_section_2_3_1_p_6">Each open call must have a matching close call. If the XOF_WARN flag is set and the name given does not match the name of the currently open container, a warning will be generated.</p> +<div id="doc_figure_u.78"></div> <pre> + Example: + + xo_open_container("top"); + xo_open_container("system"); + xo_emit("{:host-name/%s%s%s", hostname, + domainname ? "." : "", domainname ?: ""); + xo_close_container("system"); + xo_close_container("top"); + + Sample Output: + Text: + my-host.example.org + XML: + <top> + <system> + <host-name>my-host.example.org</host-name> + </system> + </top> + JSON: + "top" : { + "system" : { + "host-name": "my-host.example.org" + } + } + HTML: + <div class="data" + data-tag="host-name">my-host.example.org</div> + </pre> </div> +<div class="content"> +<h3 id="doc_section_2_3_2"> +<div class="self-section-number"> +<a href="#doc_section_2_3_2">2.3.2</a> </div> +<a id="lists-and-instances" href="#lists-and-instances">Lists and Instances</a> +</h3> +<p id="doc_section_2_3_2_p_1">A list is set of one or more instances that appear under the same parent. The instances contain details about a specific object. One can think of instances as objects or records. A call is needed to open and close the list, while a distinct call is needed to open and close each instance of the list:</p> +<div id="doc_figure_u.79"></div> <pre> + xo_open_list("item"); + + for (ip = list; ip->i_title; ip++) { + xo_open_instance("item"); + xo_emit("{L:Item} '{:name/%s}':\n", ip->i_title); + xo_close_instance("item"); + } + + xo_close_list("item"); + </pre> <p id="doc_section_2_3_2_p_3">Getting the list and instance calls correct is critical to the proper generation of XML and JSON data.</p> +</div> +<div class="content"> +<h3 id="doc_section_2_3_3"> +<div class="self-section-number"> +<a href="#doc_section_2_3_3">2.3.3</a> </div> +<a id="dtrt-mode" href="#dtrt-mode">DTRT Mode</a> +</h3> +<p id="doc_section_2_3_3_p_1">Some users may find tracking the names of open containers, lists, and instances inconvenient. libxo offers a "Do The Right Thing" mode, where libxo will track the names of open containers, lists, and instances so the close function can be called without a name. To enable DTRT mode, turn on the XOF_DTRT flag prior to making any other libxo output.</p> +<div id="doc_figure_u.80"></div> <pre> + xo_set_flags(NULL, XOF_DTRT); + </pre> <p id="doc_section_2_3_3_p_3">Each open and close function has a version with the suffix "_d", which will close the open container, list, or instance:</p> +<div id="doc_figure_u.81"></div> <pre> + xo_open_container("top"); + ... + xo_close_container_d(); + </pre> <p id="doc_section_2_3_3_p_5">This also works for lists and instances:</p> +<div id="doc_figure_u.82"></div> <pre> + xo_open_list("item"); + for (...) { + xo_open_instance("item"); + xo_emit(...); + xo_close_instance_d(); + } + xo_close_list_d(); + </pre> <p id="doc_section_2_3_3_p_7">Note that the XOF_WARN flag will also cause libxo to track open containers, lists, and instances. A warning is generated when the name given to the close function and the name recorded do not match.</p> +</div> +<div class="content"> +<h3 id="doc_section_2_3_4"> +<div class="self-section-number"> +<a href="#doc_section_2_3_4">2.3.4</a> </div> +<a id="markers" href="#markers">Markers</a> +</h3> +<p id="doc_section_2_3_4_p_1">Markers are used to protect and restore the state of open constructs. While a marker is open, no other open constructs can be closed. When a marker is closed, all constructs open since the marker was opened will be closed.</p> +<p id="doc_section_2_3_4_p_2">Markers use names which are not user-visible, allowing the caller to choose appropriate internal names.</p> +<p id="doc_section_2_3_4_p_3">In this example, the code whiffles through a list of fish, calling a function to emit details about each fish. The marker "fish‑guts" is used to ensure that any constructs opened by the function are closed properly.</p> +<div id="doc_figure_u.83"></div> <pre> + for (i = 0; fish[i]; i++) { + xo_open_instance("fish"); + xo_open_marker("fish-guts"); + dump_fish_details(i); + xo_close_marker("fish-guts"); + } + </pre> </div> +</div> +<div class="content"> +<h2 id="doc_section_2_4"> +<div class="self-section-number"> +<a href="#doc_section_2_4">2.4</a> </div> <a id="command-line-arguments" href="#command-line-arguments">Command-line Arguments</a> </h2> -<p id="doc_section_2_3_p_1">libxo uses command line options to trigger rendering behavior. The following options are recognised:</p> -<p id="doc_section_2_3_p_2"> </p> +<p id="doc_section_2_4_p_1">libxo uses command line options to trigger rendering behavior. The following options are recognised:</p> +<p id="doc_section_2_4_p_2"> </p> <ul> <li>--libxo <options></li> <li>--libxo=<options></li> <li>--libxo:<brief‑options></li> </ul> -<p id="doc_section_2_3_p_3">Options is a comma-separated list of tokens that correspond to output styles, flags, or features:</p> -<div id="doc_table_u.8"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<p id="doc_section_2_4_p_3">Programs using libxo are expecting to call the xo_parse_args function to parse these arguments. See <a href="#xo_parse_args" title="Parsing Command-line Arguments (xo_parse_args)">Section 3.4.1</a> for details.</p> +<p id="doc_section_2_4_p_4">Options is a comma-separated list of tokens that correspond to output styles, flags, or features:</p> +<div id="doc_table_u.10"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Token</th> <th class="left">Action</th> @@ -24082,6 +24352,10 @@ jQuery(function ($) { <td>Do not initialize the locale setting</td> </tr> <tr> +<td>no-retain</td> +<td>Prevent retaining formatting information</td> +</tr> +<tr> <td>no-top</td> <td>Do not emit a top set of braces (JSON)</td> </tr> @@ -24094,6 +24368,10 @@ jQuery(function ($) { <td>Emit pretty-printed output</td> </tr> <tr> +<td>retain</td> +<td>Force retaining formatting information</td> +</tr> +<tr> <td>text</td> <td>Emit TEXT output</td> </tr> @@ -24123,165 +24401,7 @@ jQuery(function ($) { </tr> </tbody> </table></div> -<p id="doc_section_2_3_p_4">The brief options are detailed in <a href="#LIBXO_OPTIONS" title="LIBXO_OPTIONS">Section 3.4.6</a>.</p> -</div> -<div class="content"> -<h2 id="doc_section_2_4"> -<div class="self-section-number"> -<a href="#doc_section_2_4">2.4</a> </div> -<a id="representing-hierarchy" href="#representing-hierarchy">Representing Hierarchy</a> -</h2> -<p id="doc_section_2_4_p_1">For XML and JSON, individual fields appear inside hierarchies which provide context and meaning to the fields. Unfortunately, these encoding have a basic disconnect between how lists is similar objects are represented.</p> -<p id="doc_section_2_4_p_2">XML encodes lists as set of sequential elements:</p> -<div id="doc_figure_u.68"></div> <pre> - <user>phil</user> - <user>pallavi</user> - <user>sjg</user> - </pre> <p id="doc_section_2_4_p_4">JSON encodes lists using a single name and square brackets:</p> -<div id="doc_figure_u.69"></div> <pre> - "user": [ "phil", "pallavi", "sjg" ] - </pre> <p id="doc_section_2_4_p_6">This means libxo needs three distinct indications of hierarchy: one for containers of hierarchy appear only once for any specific parent, one for lists, and one for each item in a list.</p> -<p id="doc_section_2_4_p_7">Section Contents: </p> -<ul> -<li><a href="#containers" title="Containers">Section 2.4.1</a></li> -<li><a href="#lists-and-instances" title="Lists and Instances">Section 2.4.2</a></li> -<li><a href="#dtrt-mode" title="DTRT Mode">Section 2.4.3</a></li> -<li><a href="#markers" title="Markers">Section 2.4.4</a></li> -</ul> -<div class="content"> -<h3 id="doc_section_2_4_1"> -<div class="self-section-number"> -<a href="#doc_section_2_4_1">2.4.1</a> </div> -<a id="containers" href="#containers">Containers</a> -</h3> -<p id="doc_section_2_4_1_p_1">A "container" is an element of a hierarchy that appears only once under any specific parent. The container has no value, but serves to contain other nodes.</p> -<p id="doc_section_2_4_1_p_2">To open a container, call xo_open_container() or xo_open_container_h(). The former uses the default handle and the latter accepts a specific handle.</p> -<div id="doc_figure_u.70"></div> <pre> - int xo_open_container_h (xo_handle_t *xop, const char *name); - int xo_open_container (const char *name); - </pre> <p id="doc_section_2_4_1_p_4">To close a level, use the xo_close_container() or xo_close_container_h() functions:</p> -<div id="doc_figure_u.71"></div> <pre> - int xo_close_container_h (xo_handle_t *xop, const char *name); - int xo_close_container (const char *name); - </pre> <p id="doc_section_2_4_1_p_6">Each open call must have a matching close call. If the XOF_WARN flag is set and the name given does not match the name of the currently open container, a warning will be generated.</p> -<div id="doc_figure_u.72"></div> <pre> - Example: - - xo_open_container("top"); - xo_open_container("system"); - xo_emit("{:host-name/%s%s%s", hostname, - domainname ? "." : "", domainname ?: ""); - xo_close_container("system"); - xo_close_container("top"); - - Sample Output: - Text: - my-host.example.org - XML: - <top> - <system> - <host-name>my-host.example.org</host-name> - </system> - </top> - JSON: - "top" : { - "system" : { - "host-name": "my-host.example.org" - } - } - HTML: - <div class="data" - data-tag="host-name">my-host.example.org</div> - </pre> </div> -<div class="content"> -<h3 id="doc_section_2_4_2"> -<div class="self-section-number"> -<a href="#doc_section_2_4_2">2.4.2</a> </div> -<a id="lists-and-instances" href="#lists-and-instances">Lists and Instances</a> -</h3> -<p id="doc_section_2_4_2_p_1">A list is set of one or more instances that appear under the same parent. The instances contain details about a specific object. One can think of instances as objects or records. A call is needed to open and close the list, while a distinct call is needed to open and close each instance of the list:</p> -<div id="doc_figure_u.73"></div> <pre> - xo_open_list("item"); - - for (ip = list; ip->i_title; ip++) { - xo_open_instance("item"); - xo_emit("{L:Item} '{:name/%s}':\n", ip->i_title); - xo_close_instance("item"); - } - - xo_close_list("item"); - </pre> <p id="doc_section_2_4_2_p_3">Getting the list and instance calls correct is critical to the proper generation of XML and JSON data.</p> -</div> -<div class="content"> -<h3 id="doc_section_2_4_3"> -<div class="self-section-number"> -<a href="#doc_section_2_4_3">2.4.3</a> </div> -<a id="dtrt-mode" href="#dtrt-mode">DTRT Mode</a> -</h3> -<p id="doc_section_2_4_3_p_1">Some users may find tracking the names of open containers, lists, and instances inconvenient. libxo offers a "Do The Right Thing" mode, where libxo will track the names of open containers, lists, and instances so the close function can be called without a name. To enable DTRT mode, turn on the XOF_DTRT flag prior to making any other libxo output.</p> -<div id="doc_figure_u.74"></div> <pre> - xo_set_flags(NULL, XOF_DTRT); - </pre> <p id="doc_section_2_4_3_p_3">Each open and close function has a version with the suffix "_d", which will close the open container, list, or instance:</p> -<div id="doc_figure_u.75"></div> <pre> - xo_open_container("top"); - ... - xo_close_container_d(); - </pre> <p id="doc_section_2_4_3_p_5">This also works for lists and instances:</p> -<div id="doc_figure_u.76"></div> <pre> - xo_open_list("item"); - for (...) { - xo_open_instance("item"); - xo_emit(...); - xo_close_instance_d(); - } - xo_close_list_d(); - </pre> <p id="doc_section_2_4_3_p_7">Note that the XOF_WARN flag will also cause libxo to track open containers, lists, and instances. A warning is generated when the name given to the close function and the name recorded do not match.</p> -</div> -<div class="content"> -<h3 id="doc_section_2_4_4"> -<div class="self-section-number"> -<a href="#doc_section_2_4_4">2.4.4</a> </div> -<a id="markers" href="#markers">Markers</a> -</h3> -<p id="doc_section_2_4_4_p_1">Markers are used to protect and restore the state of open constructs. While a marker is open, no other open constructs can be closed. When a marker is closed, all constructs open since the marker was opened will be closed.</p> -<p id="doc_section_2_4_4_p_2">Markers use names which are not user-visible, allowing the caller to choose appropriate internal names.</p> -<p id="doc_section_2_4_4_p_3">In this example, the code whiffles through a list of fish, calling a function to emit details about each fish. The marker "fish‑guts" is used to ensure that any constructs opened by the function are closed properly.</p> -<div id="doc_figure_u.77"></div> <pre> - for (i = 0; fish[i]; i++) { - xo_open_instance("fish"); - xo_open_marker("fish-guts"); - dump_fish_details(i); - xo_close_marker("fish-guts"); - } - </pre> </div> -</div> -<div class="content"> -<h2 id="doc_section_2_5"> -<div class="self-section-number"> -<a href="#doc_section_2_5">2.5</a> </div> -<a id="handles" href="#handles">Handles</a> -</h2> -<p id="doc_section_2_5_p_1">libxo uses "handles" to control its rendering functionality. The handle contains state and buffered data, as well as callback functions to process data.</p> -<p id="doc_section_2_5_p_2">A default handle is used when a NULL is passed to functions accepting a handle. This handle is initialized to write its data to stdout using the default style of text (XO_STYLE_TEXT).</p> -<p id="doc_section_2_5_p_3">For the convenience of callers, the libxo library includes handle-less functions that implicitly use the default handle. Any function that takes a handle will use the default handle is a value of NULL is passed in place of a valid handle.</p> -<p id="doc_section_2_5_p_4">For example, the following are equivalent:</p> -<div id="doc_figure_u.78"></div> <pre> - xo_emit("test"); - xo_emit_h(NULL, "test"); - </pre> <p id="doc_section_2_5_p_6">Handles are created using xo_create() and destroy using xo_destroy().</p> -</div> -<div class="content"> -<h2 id="doc_section_2_6"> -<div class="self-section-number"> -<a href="#doc_section_2_6">2.6</a> </div> -<a id="utf-8" href="#utf-8">UTF-8</a> -</h2> -<p id="doc_section_2_6_p_1">All strings for libxo must be UTF-8. libxo will handle turning them into locale-based strings for display to the user.</p> -<p id="doc_section_2_6_p_2">The only exception is argument formatted using the "%ls" format, which require a wide character string (wchar_t *) as input. libxo will convert these arguments as needed to either UTF-8 (for XML, JSON, and HTML styles) or locale-based strings for display in text style.</p> -<div id="doc_figure_u.79"></div> <pre> - xo_emit("Alll strings are utf-8 content {:tag/%ls}", - L"except for wide strings"); - </pre> <p id="doc_section_2_6_p_4">"%S" is equivalent to "%ls".</p> +<p id="doc_section_2_4_p_5">The brief options are detailed in <a href="#LIBXO_OPTIONS" title="LIBXO_OPTIONS">Section 3.4.6</a>.</p> </div> </div> <hr class="noprint"> @@ -24294,7 +24414,7 @@ jQuery(function ($) { <p id="doc_section_3_p_1">This section gives details about the functions in libxo, how to call them, and the actions they perform.</p> <p id="doc_section_3_p_2">Section Contents: </p> <ul> -<li><a href="#handles-2" title="Handles">Section 3.1</a></li> +<li><a href="#handles" title="Handles">Section 3.1</a></li> <li><a href="#emitting-content-xo_emit" title="Emitting Content (xo_emit)">Section 3.2</a></li> <li><a href="#emitting-hierarchy" title="Emitting Hierarchy">Section 3.3</a></li> <li><a href="#support-functions" title="Support Functions">Section 3.4</a></li> @@ -24305,13 +24425,19 @@ jQuery(function ($) { <h2 id="doc_section_3_1"> <div class="self-section-number"> <a href="#doc_section_3_1">3.1</a> </div> -<a id="handles-2" href="#handles-2">Handles</a> +<a id="handles" href="#handles">Handles</a> </h2> -<p id="doc_section_3_1_p_1">Handles give an abstraction for libxo that encapsulates the state of a stream of output. Handles have the data type "xo_handle_t" and are opaque to the caller.</p> -<p id="doc_section_3_1_p_2">The library has a default handle that is automatically initialized. By default, this handle will send text style output to standard output. The xo_set_style and xo_set_flags functions can be used to change this behavior.</p> -<p id="doc_section_3_1_p_3">Many libxo functions take a handle as their first parameter; most that do not use the default handle. Any function taking a handle can be passed NULL to access the default handle.</p> +<p id="doc_section_3_1_p_1">libxo uses "handles" to control its rendering functionality. The handle contains state and buffered data, as well as callback functions to process data.</p> +<p id="doc_section_3_1_p_2">Handles give an abstraction for libxo that encapsulates the state of a stream of output. Handles have the data type "xo_handle_t" and are opaque to the caller.</p> +<p id="doc_section_3_1_p_3">The library has a default handle that is automatically initialized. By default, this handle will send text style output (XO_STYLE_TEXT) to standard output. The xo_set_style and xo_set_flags functions can be used to change this behavior.</p> <p id="doc_section_3_1_p_4">For the typical command that is generating output on standard output, there is no need to create an explicit handle, but they are available when needed, e.g., for daemons that generate multiple streams of output.</p> -<p id="doc_section_3_1_p_5">Section Contents: </p> +<p id="doc_section_3_1_p_5">Many libxo functions take a handle as their first parameter; most that do not use the default handle. Any function taking a handle can be passed NULL to access the default handle. For the convenience of callers, the libxo library includes handle-less functions that implicitly use the default handle.</p> +<p id="doc_section_3_1_p_6">For example, the following are equivalent:</p> +<div id="doc_figure_u.84"></div> <pre> + xo_emit("test"); + xo_emit_h(NULL, "test"); + </pre> <p id="doc_section_3_1_p_8">Handles are created using xo_create() and destroy using xo_destroy().</p> +<p id="doc_section_3_1_p_9">Section Contents: </p> <ul> <li><a href="#xo_create" title="xo_create">Section 3.1.1</a></li> <li><a href="#xo_create_to_file" title="xo_create_to_file">Section 3.1.2</a></li> @@ -24327,7 +24453,7 @@ jQuery(function ($) { <a id="xo_create" href="#xo_create">xo_create</a> </h3> <p id="doc_section_3_1_1_p_1">A handle can be allocated using the xo_create() function:</p> -<div id="doc_figure_u.80"></div> <pre> +<div id="doc_figure_u.85"></div> <pre> xo_handle_t *xo_create (unsigned style, unsigned flags); Example: @@ -24343,7 +24469,7 @@ jQuery(function ($) { <a id="xo_create_to_file" href="#xo_create_to_file">xo_create_to_file</a> </h3> <p id="doc_section_3_1_2_p_1">By default, libxo writes output to standard output. A convenience function is provided for situations when output should be written to a different file:</p> -<div id="doc_figure_u.81"></div> <pre> +<div id="doc_figure_u.86"></div> <pre> xo_handle_t *xo_create_to_file (FILE *fp, unsigned style, unsigned flags); </pre> <p id="doc_section_3_1_2_p_3">Use the XOF_CLOSE_FP flag to trigger a call to fclose() for the FILE pointer when the handle is destroyed.</p> @@ -24355,7 +24481,7 @@ jQuery(function ($) { <a id="xo_set_writer" href="#xo_set_writer">xo_set_writer</a> </h3> <p id="doc_section_3_1_3_p_1">The xo_set_writer function allows custom 'write' functions which can tailor how libxo writes data. An opaque argument is recorded and passed back to the write function, allowing the function to acquire context information. The 'close' function can release this opaque data and any other resources as needed. The flush function can flush buffered data associated with the opaque object.</p> -<div id="doc_figure_u.82"></div> <pre> +<div id="doc_figure_u.87"></div> <pre> void xo_set_writer (xo_handle_t *xop, void *opaque, xo_write_func_t write_func, xo_close_func_t close_func); @@ -24368,10 +24494,10 @@ jQuery(function ($) { <a id="xo_set_style" href="#xo_set_style">xo_set_style</a> </h3> <p id="doc_section_3_1_4_p_1">To set the style, use the xo_set_style() function:</p> -<div id="doc_figure_u.83"></div> <pre> +<div id="doc_figure_u.88"></div> <pre> void xo_set_style(xo_handle_t *xop, unsigned style); </pre> <p id="doc_section_3_1_4_p_3">To use the default handle, pass a NULL handle:</p> -<div id="doc_figure_u.84"></div> <pre> +<div id="doc_figure_u.89"></div> <pre> xo_set_style(NULL, XO_STYLE_XML); </pre> <p id="doc_section_3_1_4_p_5">Section Contents: </p> <ul> @@ -24385,7 +24511,7 @@ jQuery(function ($) { <a id="styles" href="#styles">Output Styles (XO_STYLE_*)</a> </h4> <p id="doc_section_3_1_4_1_p_1">The libxo functions accept a set of output styles:</p> -<div id="doc_table_u.9"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.11"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Flag</th> <th class="left">Description</th> @@ -24417,10 +24543,10 @@ jQuery(function ($) { <a id="xo_set_style_name" href="#xo_set_style_name">xo_set_style_name</a> </h4> <p id="doc_section_3_1_4_2_p_1">The xo_set_style_name() can be used to set the style based on a name encoded as a string:</p> -<div id="doc_figure_u.85"></div> <pre> +<div id="doc_figure_u.90"></div> <pre> int xo_set_style_name (xo_handle_t *xop, const char *style); </pre> <p id="doc_section_3_1_4_2_p_3">The name can be any of the styles: "text", "xml", "json", or "html".</p> -<div id="doc_figure_u.86"></div> <pre> +<div id="doc_figure_u.91"></div> <pre> EXAMPLE: xo_set_style_name(NULL, "html"); </pre> </div> @@ -24432,10 +24558,10 @@ jQuery(function ($) { <a id="xo_set_flags" href="#xo_set_flags">xo_set_flags</a> </h3> <p id="doc_section_3_1_5_p_1">To set the flags, use the xo_set_flags() function:</p> -<div id="doc_figure_u.87"></div> <pre> +<div id="doc_figure_u.92"></div> <pre> void xo_set_flags(xo_handle_t *xop, unsigned flags); </pre> <p id="doc_section_3_1_5_p_3">To use the default handle, pass a NULL handle:</p> -<div id="doc_figure_u.88"></div> <pre> +<div id="doc_figure_u.93"></div> <pre> xo_set_style(NULL, XO_STYLE_XML); </pre> <p id="doc_section_3_1_5_p_5">Section Contents: </p> <ul> @@ -24450,7 +24576,7 @@ jQuery(function ($) { <a id="flags" href="#flags">Flags (XOF_*)</a> </h4> <p id="doc_section_3_1_5_1_p_1">The set of valid flags include:</p> -<div id="doc_table_u.10"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.12"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Flag</th> <th class="left">Description</th> @@ -24528,7 +24654,7 @@ jQuery(function ($) { <p id="doc_section_3_1_5_1_p_5">The XOF_WARN flag requests that warnings will trigger diagnostic output (on standard error) when the library notices errors during operations, or with arguments to functions. Without warnings enabled, such conditions are ignored.</p> <p id="doc_section_3_1_5_1_p_6">Warnings allow developers to debug their interaction with libxo. The function "xo_failure" can used as a breakpoint for a debugger, regardless of whether warnings are enabled.</p> <p id="doc_section_3_1_5_1_p_7">If the style is XO_STYLE_HTML, the following additional flags can be used:</p> -<div id="doc_table_u.11"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.13"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Flag</th> <th class="left">Description</th> @@ -24547,7 +24673,7 @@ jQuery(function ($) { <p id="doc_section_3_1_5_1_p_8">The XOF_XPATH flag enables the emission of XPath expressions detailing the hierarchy of XML elements used to encode the data field, if the XPATH style of output were requested.</p> <p id="doc_section_3_1_5_1_p_9">The XOF_INFO flag encodes additional informational fields for HTML output. See <a href="#info" title="Field Information (xo_info_t)">Section 3.4.4</a> for details.</p> <p id="doc_section_3_1_5_1_p_10">If the style is XO_STYLE_XML, the following additional flags can be used:</p> -<div id="doc_table_u.12"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.14"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Flag</th> <th class="left">Description</th> @@ -24558,7 +24684,7 @@ jQuery(function ($) { </tr></tbody> </table></div> <p id="doc_section_3_1_5_1_p_11">The XOF_KEYS flag adds 'key' attribute to the XML encoding for field definitions that use the 'k' modifier. The key attribute has the value "key":</p> -<div id="doc_figure_u.89"></div> <pre> +<div id="doc_figure_u.94"></div> <pre> xo_emit("{k:name}", item); XML: @@ -24571,7 +24697,7 @@ jQuery(function ($) { <a id="xo_clear_flags" href="#xo_clear_flags">xo_clear_flags</a> </h4> <p id="doc_section_3_1_5_2_p_1">The xo_clear_flags() function turns off the given flags in a specific handle.</p> -<div id="doc_figure_u.90"></div> <pre> +<div id="doc_figure_u.95"></div> <pre> void xo_clear_flags (xo_handle_t *xop, xo_xof_flags_t flags); </pre> </div> <div class="content"> @@ -24581,9 +24707,9 @@ jQuery(function ($) { <a id="xo_set_options" href="#xo_set_options">xo_set_options</a> </h4> <p id="doc_section_3_1_5_3_p_1">The xo_set_options() function accepts a comma-separated list of styles and flags and enables them for a specific handle.</p> -<div id="doc_figure_u.91"></div> <pre> +<div id="doc_figure_u.96"></div> <pre> int xo_set_options (xo_handle_t *xop, const char *input); - </pre> <p id="doc_section_3_1_5_3_p_3">The options are identical to those listed in <a href="#command-line-arguments" title="Command-line Arguments">Section 2.3</a>.</p> + </pre> <p id="doc_section_3_1_5_3_p_3">The options are identical to those listed in <a href="#command-line-arguments" title="Command-line Arguments">Section 2.4</a>.</p> </div> </div> <div class="content"> @@ -24593,7 +24719,7 @@ jQuery(function ($) { <a id="xo_destroy" href="#xo_destroy">xo_destroy</a> </h3> <p id="doc_section_3_1_6_p_1">The xo_destroy function releases a handle and any resources it is using. Calling xo_destroy with a NULL handle will release any resources associated with the default handle.</p> -<div id="doc_figure_u.92"></div> <pre> +<div id="doc_figure_u.97"></div> <pre> void xo_destroy(xo_handle_t *xop); </pre> </div> </div> @@ -24604,33 +24730,57 @@ jQuery(function ($) { <a id="emitting-content-xo_emit" href="#emitting-content-xo_emit">Emitting Content (xo_emit)</a> </h2> <p id="doc_section_3_2_p_1">The following functions are used to emit output:</p> -<div id="doc_figure_u.93"></div> <pre> +<div id="doc_figure_u.98"></div> <pre> int xo_emit (const char *fmt, ...); int xo_emit_h (xo_handle_t *xop, const char *fmt, ...); int xo_emit_hv (xo_handle_t *xop, const char *fmt, va_list vap); - </pre> <p id="doc_section_3_2_p_3">The "fmt" argument is a string containing field descriptors as specified in <a href="#format-strings" title="Format Strings">Section 2.2</a>. The use of a handle is optional and NULL can be passed to access the internal 'default' handle. See <a href="#handles" title="Handles">Section 2.5</a>.</p> + </pre> <p id="doc_section_3_2_p_3">The "fmt" argument is a string containing field descriptors as specified in <a href="#format-strings" title="Format Strings">Section 2.2</a>. The use of a handle is optional and NULL can be passed to access the internal 'default' handle. See <a href="#handles" title="Handles">Section 3.1</a>.</p> <p id="doc_section_3_2_p_4">The remaining arguments to xo_emit() and xo_emit_h() are a set of arguments corresponding to the fields in the format string. Care must be taken to ensure the argument types match the fields in the format string, since an inappropriate cast can ruin your day. The vap argument to xo_emit_hv() points to a variable argument list that can be used to retrieve arguments via va_arg().</p> <p id="doc_section_3_2_p_5">Section Contents: </p> <ul> -<li><a href="#xo_attr" title="Attributes (xo_attr)">Section 3.2.1</a></li> -<li><a href="#flushing-output-xo_flush" title="Flushing Output (xo_flush)">Section 3.2.2</a></li> -<li><a href="#finishing-output-xo_finish" title="Finishing Output (xo_finish)">Section 3.2.3</a></li> +<li><a href="#xo_emit_field" title="Single Field Emitting Functions (xo_emit_field)">Section 3.2.1</a></li> +<li><a href="#xo_attr" title="Attributes (xo_attr)">Section 3.2.2</a></li> +<li><a href="#flushing-output-xo_flush" title="Flushing Output (xo_flush)">Section 3.2.3</a></li> +<li><a href="#finishing-output-xo_finish" title="Finishing Output (xo_finish)">Section 3.2.4</a></li> </ul> <div class="content"> <h3 id="doc_section_3_2_1"> <div class="self-section-number"> <a href="#doc_section_3_2_1">3.2.1</a> </div> +<a id="xo_emit_field" href="#xo_emit_field">Single Field Emitting Functions (xo_emit_field)</a> +</h3> +<p id="doc_section_3_2_1_p_1">The following functions can also make output, but only make a single field at a time:</p> +<div id="doc_figure_u.99"></div> <pre> + int xo_emit_field_hv (xo_handle_t *xop, const char *rolmod, + const char *contents, const char *fmt, + const char *efmt, va_list vap); + + int xo_emit_field_h (xo_handle_t *xop, const char *rolmod, + const char *contents, const char *fmt, + const char *efmt, ...); + + int xo_emit_field (const char *rolmod, const char *contents, + const char *fmt, const char *efmt, ...); + </pre> <p id="doc_section_3_2_1_p_3">These functions are intended to avoid the scenario where one would otherwise need to compose a format descriptors using snprintf(). The individual parts of the format descriptor are passed in distinctly.</p> +<div id="doc_figure_u.100"></div> <pre> + xo_emit("T", "Host name is ", NULL, NULL); + xo_emit("V", "host-name", NULL, NULL, host-name); + </pre> </div> +<div class="content"> +<h3 id="doc_section_3_2_2"> +<div class="self-section-number"> +<a href="#doc_section_3_2_2">3.2.2</a> </div> <a id="xo_attr" href="#xo_attr">Attributes (xo_attr)</a> </h3> -<p id="doc_section_3_2_1_p_1">The xo_attr() function emits attributes for the XML output style.</p> -<div id="doc_figure_u.94"></div> <pre> +<p id="doc_section_3_2_2_p_1">The xo_attr() function emits attributes for the XML output style.</p> +<div id="doc_figure_u.101"></div> <pre> int xo_attr (const char *name, const char *fmt, ...); int xo_attr_h (xo_handle_t *xop, const char *name, const char *fmt, ...); int xo_attr_hv (xo_handle_t *xop, const char *name, const char *fmt, va_list vap); - </pre> <p id="doc_section_3_2_1_p_3">The name parameter give the name of the attribute to be encoded. The fmt parameter gives a printf-style format string used to format the value of the attribute using any remaining arguments, or the vap parameter passed to xo_attr_hv().</p> -<div id="doc_figure_u.95"></div> <pre> + </pre> <p id="doc_section_3_2_2_p_3">The name parameter give the name of the attribute to be encoded. The fmt parameter gives a printf-style format string used to format the value of the attribute using any remaining arguments, or the vap parameter passed to xo_attr_hv().</p> +<div id="doc_figure_u.102"></div> <pre> EXAMPLE: xo_attr("seconds", "%ld", (unsigned long) login_time); struct tm *tmp = localtime(login_time); @@ -24638,34 +24788,34 @@ jQuery(function ($) { xo_emit("Logged in at {:login-time}\n", buf); XML: <login-time seconds="1408336270">00:14</login-time> - </pre> <p id="doc_section_3_2_1_p_5">xo_attr is placed on the next container, instance, leaf, or leaf list that is emitted.</p> -<p id="doc_section_3_2_1_p_6">Since attributes are only emitted in XML, their use should be limited to meta-data and additional or redundant representations of data already emitted in other form.</p> + </pre> <p id="doc_section_3_2_2_p_5">xo_attr is placed on the next container, instance, leaf, or leaf list that is emitted.</p> +<p id="doc_section_3_2_2_p_6">Since attributes are only emitted in XML, their use should be limited to meta-data and additional or redundant representations of data already emitted in other form.</p> </div> <div class="content"> -<h3 id="doc_section_3_2_2"> +<h3 id="doc_section_3_2_3"> <div class="self-section-number"> -<a href="#doc_section_3_2_2">3.2.2</a> </div> +<a href="#doc_section_3_2_3">3.2.3</a> </div> <a id="flushing-output-xo_flush" href="#flushing-output-xo_flush">Flushing Output (xo_flush)</a> </h3> -<p id="doc_section_3_2_2_p_1">libxo buffers data, both for performance and consistency, but also to allow some advanced features to work properly. At various times, the caller may wish to flush any data buffered within the library. The xo_flush() call is used for this:</p> -<div id="doc_figure_u.96"></div> <pre> +<p id="doc_section_3_2_3_p_1">libxo buffers data, both for performance and consistency, but also to allow some advanced features to work properly. At various times, the caller may wish to flush any data buffered within the library. The xo_flush() call is used for this:</p> +<div id="doc_figure_u.103"></div> <pre> void xo_flush (void); void xo_flush_h (xo_handle_t *xop); - </pre> <p id="doc_section_3_2_2_p_3">Calling xo_flush also triggers the flush function associated with the handle. For the default handle, this is equivalent to "fflush(stdio);".</p> + </pre> <p id="doc_section_3_2_3_p_3">Calling xo_flush also triggers the flush function associated with the handle. For the default handle, this is equivalent to "fflush(stdio);".</p> </div> <div class="content"> -<h3 id="doc_section_3_2_3"> +<h3 id="doc_section_3_2_4"> <div class="self-section-number"> -<a href="#doc_section_3_2_3">3.2.3</a> </div> +<a href="#doc_section_3_2_4">3.2.4</a> </div> <a id="finishing-output-xo_finish" href="#finishing-output-xo_finish">Finishing Output (xo_finish)</a> </h3> -<p id="doc_section_3_2_3_p_1">When the program is ready to exit or close a handle, a call to xo_finish() is required. This flushes any buffered data, closes open libxo constructs, and completes any pending operations.</p> -<div id="doc_figure_u.97"></div> <pre> +<p id="doc_section_3_2_4_p_1">When the program is ready to exit or close a handle, a call to xo_finish() is required. This flushes any buffered data, closes open libxo constructs, and completes any pending operations.</p> +<div id="doc_figure_u.104"></div> <pre> int xo_finish (void); int xo_finish_h (xo_handle_t *xop); void xo_finish_atexit (void); - </pre> <p id="doc_section_3_2_3_p_3">Calling this function is vital to the proper operation of libxo, especially for the non-TEXT output styles.</p> -<p id="doc_section_3_2_3_p_4">xo_finish_atexit is suitable for use with atexit(3).</p> + </pre> <p id="doc_section_3_2_4_p_3">Calling this function is vital to the proper operation of libxo, especially for the non-TEXT output styles.</p> +<p id="doc_section_3_2_4_p_4">xo_finish_atexit is suitable for use with atexit(3).</p> </div> </div> <div class="content"> @@ -24676,7 +24826,7 @@ jQuery(function ($) { </h2> <p id="doc_section_3_3_p_1">libxo represents to types of hierarchy: containers and lists. A container appears once under a given parent where a list contains instances that can appear multiple times. A container is used to hold related fields and to give the data organization and scope.</p> <p id="doc_section_3_3_p_2">To create a container, use the xo_open_container and xo_close_container functions:</p> -<div id="doc_figure_u.98"></div> <pre> +<div id="doc_figure_u.105"></div> <pre> int xo_open_container (const char *name); int xo_open_container_h (xo_handle_t *xop, const char *name); int xo_open_container_hd (xo_handle_t *xop, const char *name); @@ -24690,7 +24840,7 @@ jQuery(function ($) { <p id="doc_section_3_3_p_5">The close functions with the "_d" suffix are used in "Do The Right Thing" mode, where the name of the open containers, lists, and instances are maintained internally by libxo to allow the caller to avoid keeping track of the open container name.</p> <p id="doc_section_3_3_p_6">Use the XOF_WARN flag to generate a warning if the name given on the close does not match the current open container.</p> <p id="doc_section_3_3_p_7">For TEXT and HTML output, containers are not rendered into output text, though for HTML they are used when the XOF_XPATH flag is set.</p> -<div id="doc_figure_u.99"></div> <pre> +<div id="doc_figure_u.106"></div> <pre> EXAMPLE: xo_open_container("system"); xo_emit("The host name is {:host-name}\n", hn); @@ -24707,7 +24857,7 @@ jQuery(function ($) { </h3> <p id="doc_section_3_3_1_p_1">Lists are sequences of instances of homogeneous data objects. Two distinct levels of calls are needed to represent them in our output styles. Calls must be made to open and close a list, and for each instance of data in that list, calls must be make to open and close that instance.</p> <p id="doc_section_3_3_1_p_2">The name given to all calls must be identical, and it is strongly suggested that the name be singular, not plural, as a matter of style and usage expectations.</p> -<div id="doc_figure_u.100"></div> <pre> +<div id="doc_figure_u.107"></div> <pre> EXAMPLE: xo_open_list("user"); for (i = 0; i < num_users; i++) { @@ -24776,11 +24926,11 @@ jQuery(function ($) { <a id="xo_parse_args" href="#xo_parse_args">Parsing Command-line Arguments (xo_parse_args)</a> </h3> <p id="doc_section_3_4_1_p_1">The xo_parse_args() function is used to process a program's arguments. libxo-specific options are processed and removed from the argument list so the calling application does not need to process them. If successful, a new value for argc is returned. On failure, a message it emitted and -1 is returned.</p> -<div id="doc_figure_u.101"></div> <pre> +<div id="doc_figure_u.108"></div> <pre> argc = xo_parse_args(argc, argv); if (argc < 0) exit(EXIT_FAILURE); - </pre> <p id="doc_section_3_4_1_p_3">Following the call to xo_parse_args, the application can process the remaining arguments in a normal manner. See <a href="#command-line-arguments" title="Command-line Arguments">Section 2.3</a> for a description of valid arguments.</p> + </pre> <p id="doc_section_3_4_1_p_3">Following the call to xo_parse_args, the application can process the remaining arguments in a normal manner. See <a href="#command-line-arguments" title="Command-line Arguments">Section 2.4</a> for a description of valid arguments.</p> </div> <div class="content"> <h3 id="doc_section_3_4_2"> @@ -24789,7 +24939,7 @@ jQuery(function ($) { <a id="xo_set_program" href="#xo_set_program">xo_set_program</a> </h3> <p id="doc_section_3_4_2_p_1">The xo_set_program function sets name of the program as reported by functions like xo_failure, xo_warn, xo_err, etc. The program name is initialized by xo_parse_args, but subsequent calls to xo_set_program can override this value.</p> -<div id="doc_figure_u.102"></div> <pre> +<div id="doc_figure_u.109"></div> <pre> xo_set_program(argv[0]); </pre> <p id="doc_section_3_4_2_p_3">Note that the value is not copied, so the memory passed to xo_set_program (and xo_parse_args) must be maintained by the caller.</p> </div> @@ -24800,7 +24950,7 @@ jQuery(function ($) { <a id="xo_set_version" href="#xo_set_version">xo_set_version</a> </h3> <p id="doc_section_3_4_3_p_1">The xo_set_version function records a version number to be emitted as part of the data for encoding styles (XML and JSON). This version number is suitable for tracking changes in the content, allowing a user of the data to discern which version of the data model is in use.</p> -<div id="doc_figure_u.103"></div> <pre> +<div id="doc_figure_u.110"></div> <pre> void xo_set_version (const char *version); void xo_set_version_h (xo_handle_t *xop, const char *version); </pre> </div> @@ -24813,7 +24963,7 @@ jQuery(function ($) { <p id="doc_section_3_4_4_p_1">HTML data can include additional information in attributes that begin with "data‑". To enable this, three things must occur:</p> <p id="doc_section_3_4_4_p_2">First the application must build an array of xo_info_t structures, one per tag. The array must be sorted by name, since libxo uses a binary search to find the entry that matches names from format instructions.</p> <p id="doc_section_3_4_4_p_3">Second, the application must inform libxo about this information using the xo_set_info() call:</p> -<div id="doc_figure_u.104"></div> <pre> +<div id="doc_figure_u.111"></div> <pre> typedef struct xo_info_s { const char *xi_name; /* Name of the element */ const char *xi_type; /* Type of field */ @@ -24823,7 +24973,7 @@ jQuery(function ($) { void xo_set_info (xo_handle_t *xop, xo_info_t *infop, int count); </pre> <p id="doc_section_3_4_4_p_5">Like other libxo calls, passing NULL for the handle tells libxo to use the default handle.</p> <p id="doc_section_3_4_4_p_6">If the count is -1, libxo will count the elements of infop, but there must be an empty element at the end. More typically, the number is known to the application:</p> -<div id="doc_figure_u.105"></div> <pre> +<div id="doc_figure_u.112"></div> <pre> xo_info_t info[] = { { "in-stock", "number", "Number of items in stock" }, { "name", "string", "Name of the item" }, @@ -24836,7 +24986,7 @@ jQuery(function ($) { xo_set_info(NULL, info, info_count); </pre> <p id="doc_section_3_4_4_p_8">Third, the emission of info must be triggered with the XOF_INFO flag using either the xo_set_flags() function or the "‑‑libxo=info" command line argument.</p> <p id="doc_section_3_4_4_p_9">The type and help values, if present, are emitted as the "data‑type" and "data‑help" attributes:</p> -<div id="doc_figure_u.106"></div> <pre> +<div id="doc_figure_u.113"></div> <pre> <div class="data" data-tag="sku" data-type="string" data-help="Stock Keeping Unit">GRO-000-533</div> </pre> </div> @@ -24847,7 +24997,7 @@ jQuery(function ($) { <a id="memory-allocation" href="#memory-allocation">Memory Allocation</a> </h3> <p id="doc_section_3_4_5_p_1">The xo_set_allocator function allows libxo to be used in environments where the standard realloc() and free() functions are not available.</p> -<div id="doc_figure_u.107"></div> <pre> +<div id="doc_figure_u.114"></div> <pre> void xo_set_allocator (xo_realloc_func_t realloc_func, xo_free_func_t free_func); </pre> <p id="doc_section_3_4_5_p_3">realloc_func should expect the same arguments as realloc(3) and return a pointer to memory following the same convention. free_func will receive the same argument as free(3) and should release it, as appropriate for the environment.</p> @@ -24860,7 +25010,7 @@ jQuery(function ($) { <a id="LIBXO_OPTIONS" href="#LIBXO_OPTIONS">LIBXO_OPTIONS</a> </h3> <p id="doc_section_3_4_6_p_1">The environment variable "LIBXO_OPTIONS" can be set to a string of options:</p> -<div id="doc_table_u.13"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.15"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Option</th> <th class="left">Action</th> @@ -24929,10 +25079,10 @@ jQuery(function ($) { </tbody> </table></div> <p id="doc_section_3_4_6_p_2">For example, warnings can be enabled by:</p> -<div id="doc_figure_u.108"></div> <pre> +<div id="doc_figure_u.115"></div> <pre> % env LIBXO_OPTIONS=W my-app </pre> <p id="doc_section_3_4_6_p_4">Complete HTML output can be generated with:</p> -<div id="doc_figure_u.109"></div> <pre> +<div id="doc_figure_u.116"></div> <pre> % env LIBXO_OPTIONS=HXI my-app </pre> <p id="doc_section_3_4_6_p_6">Since environment variables are inherited, child processes will have the same options, which may be undesirable, making the use of the "‑‑libxo" option is preferable in most situations.</p> </div> @@ -24943,7 +25093,7 @@ jQuery(function ($) { <a id="errors-warnings-and-messages" href="#errors-warnings-and-messages">Errors, Warnings, and Messages</a> </h3> <p id="doc_section_3_4_7_p_1">Many programs make use of the standard library functions err() and warn() to generate errors and warnings for the user. libxo wants to pass that information via the current output style, and provides compatible functions to allow this:</p> -<div id="doc_figure_u.110"></div> <pre> +<div id="doc_figure_u.117"></div> <pre> void xo_warn (const char *fmt, ...); void xo_warnx (const char *fmt, ...); void xo_warn_c (int code, const char *fmt, ...); @@ -24959,7 +25109,7 @@ jQuery(function ($) { void xo_message_hcv (xo_handle_t *xop, int code, const char *fmt, va_list vap); </pre> <p id="doc_section_3_4_7_p_3">These functions display the program name, a colon, a formatted message based on the arguments, and then optionally a colon and an error message associated with either "errno" or the "code" parameter.</p> -<div id="doc_figure_u.111"></div> <pre> +<div id="doc_figure_u.118"></div> <pre> EXAMPLE: if (open(filename, O_RDONLY) < 0) xo_err(1, "cannot open file '%s'", filename); @@ -24971,7 +25121,7 @@ jQuery(function ($) { <a id="xo_error" href="#xo_error">xo_error</a> </h3> <p id="doc_section_3_4_8_p_1">The xo_error function can be used for generic errors that should be reported over the handle, rather than to stderr. The xo_error function behaves like xo_err for TEXT and HTML output styles, but puts the error into XML or JSON elements:</p> -<div id="doc_figure_u.112"></div> <pre> +<div id="doc_figure_u.119"></div> <pre> EXAMPLE:: xo_error("Does not %s", "compute"); XML:: @@ -24986,7 +25136,7 @@ jQuery(function ($) { <a id="xo_no_setlocale" href="#xo_no_setlocale">xo_no_setlocale</a> </h3> <p id="doc_section_3_4_9_p_1">libxo automatically initializes the locale based on setting of the environment variables LC_CTYPE, LANG, and LC_ALL. The first of this list of variables is used and if none of the variables, the locale defaults to "UTF‑8". The caller may wish to avoid this behavior, and can do so by calling the xo_no_setlocale() function.</p> -<div id="doc_figure_u.113"></div> <pre> +<div id="doc_figure_u.120"></div> <pre> void xo_no_setlocale (void); </pre> </div> </div> @@ -25002,7 +25152,7 @@ jQuery(function ($) { <p id="doc_section_3_5_p_4">https://www.iana.org/assignments/enterprise-numbers/enterprise-numbers</p> <p id="doc_section_3_5_p_5">Use the <a href="#xo_set_syslog_enterprise_id" title="xo_set_syslog_enterprise_id">Section 3.5.3.5</a>() function to set the Enterprise ID, as needed.</p> <p id="doc_section_3_5_p_6">The message name should follow the conventions in <a href="#good-field-names" title="What makes a good field name?">Section 8.1.3</a>, as should the fields within the message.</p> -<div id="doc_figure_u.114"></div> <pre> +<div id="doc_figure_u.121"></div> <pre> /* Both of these calls are optional */ xo_set_syslog_enterprise_id(32473); xo_open_log("my-program", 0, LOG_DAEMON); @@ -25030,13 +25180,13 @@ jQuery(function ($) { <a id="priority" href="#priority">Priority, Facility, and Flags</a> </h3> <p id="doc_section_3_5_1_p_1">The xo_syslog, xo_vsyslog, and xo_open_log functions accept a set of flags which provide the priority of the message, the source facility, and some additional features. These values are OR'd together to create a single integer argument:</p> -<div id="doc_figure_u.115"></div> <pre> +<div id="doc_figure_u.122"></div> <pre> xo_syslog(LOG_ERR | LOG_AUTH, "login-failed", "Login failed; user '{:user}' from host '{:address}'", user, addr); </pre> <p id="doc_section_3_5_1_p_3">These values are defined in <syslog.h>.</p> <p id="doc_section_3_5_1_p_4">The priority value indicates the importance and potential impact of each message.</p> -<div id="doc_table_u.14"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.16"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Priority</th> <th class="left">Description</th> @@ -25077,7 +25227,7 @@ jQuery(function ($) { </tbody> </table></div> <p id="doc_section_3_5_1_p_5">The facility value indicates the source of message, in fairly generic terms.</p> -<div id="doc_table_u.15"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.17"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Facility</th> <th class="left">Description</th> @@ -25142,7 +25292,7 @@ jQuery(function ($) { </tbody> </table></div> <p id="doc_section_3_5_1_p_6">In addition to the values listed above, xo_open_log accepts a set of addition flags requesting specific behaviors.</p> -<div id="doc_table_u.16"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.18"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Flag</th> <th class="left">Description</th> @@ -25175,7 +25325,7 @@ jQuery(function ($) { </h3> <p id="doc_section_3_5_2_p_1">Use the xo_syslog function to generate syslog messages by calling it with a log priority and facility, a message name, a format string, and a set of arguments. The priority/facility argument are discussed above, as is the message name.</p> <p id="doc_section_3_5_2_p_2">The format string follows the same conventions as xo_emit's format string, with each field being rendered as an SD-PARAM pair.</p> -<div id="doc_figure_u.116"></div> <pre> +<div id="doc_figure_u.123"></div> <pre> xo_syslog(LOG_ERR, "poofd-missing-file", "'{:filename}' not found: {:error/%m}", filename); @@ -25204,7 +25354,7 @@ jQuery(function ($) { <a id="xo_vsyslog" href="#xo_vsyslog">xo_vsyslog</a> </h4> <p id="doc_section_3_5_3_1_p_1">xo_vsyslog is identical in function to xo_syslog, but takes the set of arguments using a va_list.</p> -<div id="doc_figure_u.117"></div> <pre> +<div id="doc_figure_u.124"></div> <pre> void my_log (const char *name, const char *fmt, ...) { va_list vap; @@ -25220,7 +25370,7 @@ jQuery(function ($) { <a id="xo_open_log" href="#xo_open_log">xo_open_log</a> </h4> <p id="doc_section_3_5_3_2_p_1">xo_open_log functions similar to openlog(3), allowing customization of the program name, the log facility number, and the additional option flags described in <a href="#priority" title="Priority, Facility, and Flags">Section 3.5.1</a>.</p> -<div id="doc_figure_u.118"></div> <pre> +<div id="doc_figure_u.125"></div> <pre> void xo_open_log (const char *ident, int logopt, int facility); </pre> </div> @@ -25231,7 +25381,7 @@ jQuery(function ($) { <a id="xo_close_log" href="#xo_close_log">xo_close_log</a> </h4> <p id="doc_section_3_5_3_3_p_1">xo_close_log functions similar to closelog(3), closing the log file and releasing any associated resources.</p> -<div id="doc_figure_u.119"></div> <pre> +<div id="doc_figure_u.126"></div> <pre> void xo_close_log (void); </pre> </div> @@ -25242,7 +25392,7 @@ jQuery(function ($) { <a id="xo_set_logmask" href="#xo_set_logmask">xo_set_logmask</a> </h4> <p id="doc_section_3_5_3_4_p_1">xo_set_logmask function similar to setlogmask(3), restricting the set of generated log event to those whose associated bit is set in maskpri. Use LOG_MASK(pri) to find the appropriate bit, or LOG_UPTO(toppri) to create a mask for all priorities up to and including toppri.</p> -<div id="doc_figure_u.120"></div> <pre> +<div id="doc_figure_u.127"></div> <pre> int xo_set_logmask (int maskpri); @@ -25257,7 +25407,7 @@ jQuery(function ($) { </h4> <p id="doc_section_3_5_3_5_p_1">Use the xo_set_syslog_enterprise_id to supply a platform- or application-specific enterprise id. This value is used in any future syslog messages.</p> <p id="doc_section_3_5_3_5_p_2">Ideally, the operating system should supply a default value via the "kern.syslog.enterprise_id" sysctl value. Lacking that, the application should provide a suitable value.</p> -<div id="doc_figure_u.121"></div> <pre> +<div id="doc_figure_u.128"></div> <pre> void xo_set_syslog_enterprise_id (unsigned short eid); </pre> <p id="doc_section_3_5_3_5_p_4">Enterprise IDs are administered by IANA, the Internet Assigned Number Authority. The complete list is EIDs on their web site:</p> @@ -25299,7 +25449,7 @@ jQuery(function ($) { <a id="loading-encoders" href="#loading-encoders">Loading Encoders</a> </h3> <p id="doc_section_3_6_1_p_1">Encoders can be registered statically or discovered dynamically. Applications can choose to call the xo_encoder_register() function to explicitly register encoders, but more typically they are built as shared libraries, placed in the libxo/extensions directory, and loaded based on name. libxo looks for a file with the name of the encoder and an extension of ".enc". This can be a file or a symlink to the shared library file that supports the encoder.</p> -<div id="doc_figure_u.122"></div> <pre> +<div id="doc_figure_u.129"></div> <pre> % ls -1 lib/libxo/extensions/*.enc lib/libxo/extensions/cbor.enc lib/libxo/extensions/test.enc @@ -25311,7 +25461,7 @@ jQuery(function ($) { <a id="encoder-initialization" href="#encoder-initialization">Encoder Initialization</a> </h3> <p id="doc_section_3_6_2_p_1">Each encoder must export a symbol used to access the library, which must have the following signature:</p> -<div id="doc_figure_u.123"></div> <pre> +<div id="doc_figure_u.130"></div> <pre> int xo_encoder_library_init (XO_ENCODER_INIT_ARGS); </pre> <p id="doc_section_3_6_2_p_3">XO_ENCODER_INIT_ARGS is a macro defined in xo_encoder.h that defines an argument called "arg", a pointer of the type xo_encoder_init_args_t. This structure contains two fields:</p> <p id="doc_section_3_6_2_p_4"> </p> @@ -25329,7 +25479,7 @@ jQuery(function ($) { <a id="operations" href="#operations">Operations</a> </h3> <p id="doc_section_3_6_3_p_1">The encoder API defines a set of operations representing the processing model of libxo. Content is formatted within libxo, and callbacks are made to the encoder's handler function when data is ready to be processed.</p> -<div id="doc_table_u.17"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.19"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Operation</th> <th class="left">Meaning (Base function)</th> @@ -25416,7 +25566,7 @@ jQuery(function ($) { <p id="doc_section_4_p_1">The "xo" utility allows command line access to the functionality of the libxo library. Using "xo", shell scripts can emit XML, JSON, and HTML using the same commands that emit text output.</p> <p id="doc_section_4_p_2">The style of output can be selected using a specific option: "‑X" for XML, "‑J" for JSON, "‑H" for HTML, or "‑T" for TEXT, which is the default. The "--style <style>" option can also be used. The LIBXO_OPTIONS environment variable can also be used to set the style, as well as other flags.</p> <p id="doc_section_4_p_3">The "xo" utility accepts a format string suitable for xo_emit() and a set of zero or more arguments used to supply data for that string.</p> -<div id="doc_figure_u.124"></div> <pre> +<div id="doc_figure_u.131"></div> <pre> xo "The {k:name} weighs {:weight/%d} pounds.\n" fish 6 TEXT: @@ -25436,7 +25586,7 @@ jQuery(function ($) { <div class="text"> pounds.</div> </div> </pre> <p id="doc_section_4_p_5">The "--wrap <path>" option can be used to wrap emitted content in a specific hierarchy. The path is a set of hierarchical names separated by the '/' character.</p> -<div id="doc_figure_u.125"></div> <pre> +<div id="doc_figure_u.132"></div> <pre> xo --wrap top/a/b/c '{:tag}' value XML: @@ -25460,7 +25610,7 @@ jQuery(function ($) { } } </pre> <p id="doc_section_4_p_7">The "--open <path>" and "--close <path>" can be used to emit hierarchical information without the matching close and open tag. This allows a shell script to emit open tags, data, and then close tags. The "‑‑depth" option may be used to set the depth for indentation. The "‑‑leading‑xpath" may be used to prepend data to the XPath values used for HTML output style.</p> -<div id="doc_figure_u.126"></div> <pre> +<div id="doc_figure_u.133"></div> <pre> #!/bin/sh xo --open top/data xo --depth 2 '{tag}' value @@ -25489,7 +25639,7 @@ jQuery(function ($) { <a id="command-line-options" href="#command-line-options">Command Line Options</a> </h2> <p id="doc_section_4_1_p_1">Usage: xo [options] format [fields]</p> -<div id="doc_figure_u.127"></div> <pre> +<div id="doc_figure_u.134"></div> <pre> --close <path> Close tags for the given path --depth <num> Set the depth for pretty printing --help Display this help text @@ -25513,7 +25663,7 @@ jQuery(function ($) { <a href="#doc_section_4_2">4.2</a> </div> <a id="example-2" href="#example-2">Example</a> </h2> -<div id="doc_figure_u.128"></div> <pre> +<div id="doc_figure_u.135"></div> <pre> % xo 'The {:product} is {:status}\n' stereo "in route" The stereo is in route % ./xo/xo -p -X 'The {:product} is {:status}\n' stereo "in route" @@ -25530,7 +25680,7 @@ jQuery(function ($) { </h1> <p id="doc_section_5_p_1">xolint is a tool for reporting common mistakes in format strings in source code that invokes xo_emit(). It allows these errors to be diagnosed at build time, rather than waiting until runtime.</p> <p id="doc_section_5_p_2">xolint takes the one or more C files as arguments, and reports and errors, warning, or informational messages as needed.</p> -<div id="doc_table_u.18"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.20"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Option</th> <th class="left">Meaning</th> @@ -25571,7 +25721,7 @@ jQuery(function ($) { </tbody> </table></div> <p id="doc_section_5_p_3">The output message will contain the source filename and line number, the class of the message, the message, and, if -p is given, the line that contains the error:</p> -<div id="doc_figure_u.129"></div> <pre> +<div id="doc_figure_u.136"></div> <pre> % xolint.pl -t xolint.c xolint.c: 16: error: anchor format should be "%d" 16 xo_emit("{[:/%s}"); @@ -25587,7 +25737,7 @@ jQuery(function ($) { </h1> <p id="doc_section_6_p_1">xohtml is a tool for turning the output of libxo-enabled commands into html files suitable for display in modern HTML web browsers. It can be used to test and debug HTML output, as well as to make the user ache to escape the world of 70s terminal devices.</p> <p id="doc_section_6_p_2">xohtml is given a command, either on the command line or via the "‑c" option. If not command is given, standard input is used. The command's output is wrapped in HTML tags, with references to supporting CSS and Javascript files, and written to standard output or the file given in the "‑f" option. The "‑b" option can be used to provide an alternative base path for the support files.</p> -<div id="doc_table_u.19"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.21"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Option</th> <th class="left">Meaning</th> @@ -25619,7 +25769,7 @@ jQuery(function ($) { <p id="doc_section_7_p_1">The "xopo" utility filters ".pot" files generated by the "xgettext" utility to remove formatting information suitable for use with the "{G:}" modifier. This means that when the developer changes the formatting portion of the field definitions, or the fields modifiers, the string passed to gettext(3) is unchanged, avoiding the expense of updating any existing translation files (".po" files).</p> <p id="doc_section_7_p_2">The syntax for the xopo command is one of two forms; it can be used as a filter for processing a .po or .pot file, rewriting the "msgid" strings with a simplified message string. In this mode, the input is either standard input or a file given by the "‑f" option, and the output is either standard output or a file given by the "‑o" option.</p> <p id="doc_section_7_p_3">In the second mode, a simple message given using the "‑s" option on the command, and the simplified version of that message is printed on stdout.</p> -<div id="doc_table_u.20"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> +<div id="doc_table_u.22"><table summary="" class="tt full" cellpadding="3" cellspacing="0"> <thead><tr> <th class="left">Option</th> <th class="left">Meaning</th> @@ -25639,7 +25789,7 @@ jQuery(function ($) { </tr> </tbody> </table></div> -<div id="doc_figure_u.130"></div> <pre> +<div id="doc_figure_u.137"></div> <pre> EXAMPLE: % xopo -s "There are {:count/%u} {:event/%.6s} events\n" There are {:count} {:event} events\n @@ -25687,9 +25837,9 @@ jQuery(function ($) { <a href="#doc_section_8_1_1">8.1.1</a> </div> <a id="can-you-share-the-history-of-libxo" href="#can-you-share-the-history-of-libxo">Can you share the history of libxo?</a> </h3> -<p id="doc_section_8_1_1_p_1">In 2001, we added an XML API to the JUNOS operating system, which is built on top of FreeBSD. Eventually this API became standardized as the NETCONF API (RFC 6241). As part of this effort, we modified many FreeBSD utilities to emit XML, typically via a "‑X" switch. The results were mixed. The cost of maintaining this code, updating it and carrying it were non-trivial, and contributed to our expense (and the associated delay) with upgrading the version of FreeBSD on which each release of JUNOS is based.</p> -<p id="doc_section_8_1_1_p_2">A recent (2014) effort within JUNOS aims at removing our modifications to the underlying FreeBSD code as a means of reducing the expense and delay. JUNOS is structured to have system components generate XML that is rendered by the CLI (think: login shell) into human-readable text. This allows the API to use the same plumbing as the CLI, and ensures that all components emit XML, and that it is emitted with knowledge of the consumer of that XML, yielding an API that have no incremental cost or feature delay.</p> -<p id="doc_section_8_1_1_p_3">libxo is an effort to mix the best aspects of the JUNOS strategy into FreeBSD in a seemless way, allowing commands to make printf-like output calls without needing to care how the output is rendered.</p> +<p id="doc_section_8_1_1_p_1">In 2001, we added an XML API to the JUNOS operating system, which is built on top of FreeBSD. Eventually this API became standardized as the NETCONF API (RFC 6241). As part of this effort, we modified many FreeBSD utilities to emit XML, typically via a "‑X" switch. The results were mixed. The cost of maintaining this code, updating it, and carrying it were non-trivial, and contributed to our expense (and the associated delay) with upgrading the version of FreeBSD on which each release of JUNOS is based.</p> +<p id="doc_section_8_1_1_p_2">A recent (2014) effort within JUNOS aims at removing our modifications to the underlying FreeBSD code as a means of reducing the expense and delay in tracking HEAD. JUNOS is structured to have system components generate XML that is rendered by the CLI (think: login shell) into human-readable text. This allows the API to use the same plumbing as the CLI, and ensures that all components emit XML, and that it is emitted with knowledge of the consumer of that XML, yielding an API that have no incremental cost or feature delay.</p> +<p id="doc_section_8_1_1_p_3">libxo is an effort to mix the best aspects of the JUNOS strategy into FreeBSD in a seemless way, allowing commands to make printf-like output calls with a single code path.</p> </div> <div class="content"> <h3 id="doc_section_8_1_2"> @@ -25698,7 +25848,7 @@ jQuery(function ($) { <a id="did-the-complex-semantics-of-format-strings-evolve-over-time" href="#did-the-complex-semantics-of-format-strings-evolve-over-time">Did the complex semantics of format strings evolve over time?</a> </h3> <p id="doc_section_8_1_2_p_1">The history is both long and short: libxo's functionality is based on what JUNOS does in a data modeling language called ODL (output definition language). In JUNOS, all subcomponents generate XML, which is feed to the CLI, where data from the ODL files tell is how to render that XML into text. ODL might had a set of tags like:</p> -<div id="doc_figure_u.131"></div> <pre> +<div id="doc_figure_u.138"></div> <pre> tag docsis-state { help "State of the DOCSIS interface"; type string; @@ -25777,7 +25927,7 @@ jQuery(function ($) { <dt>Reuse existing field names</dt> <dd>Nothing's worse than writing expressions like:</dd> </dl> -<div id="doc_figure_u.132"></div> <pre> +<div id="doc_figure_u.139"></div> <pre> if ($src1/process[pid == $pid]/name == $src2/proc-table/proc-list /proc-entry[process-id == $pid]/proc-name) { @@ -25789,7 +25939,7 @@ jQuery(function ($) { <dt>Use containment as scoping</dt> <dd>In the previous example, all the names are prefixed with "proc‑", which is redundant given that they are nested under the process table.</dd> <dt>Think about your users</dt> -<dd>Have empathy for your users, choosing clear and useful fields that contain clear and useful data. You may need to augment the display content with xo_attr() calls (<a href="#xo_attr" title="Attributes (xo_attr)">Section 3.2.1</a>) or "{e:}" fields (<a href="#e-modifier" title="The Encoding Modifier ({e:})">Section 2.2.2.3</a>) to make the data useful.</dd> +<dd>Have empathy for your users, choosing clear and useful fields that contain clear and useful data. You may need to augment the display content with xo_attr() calls (<a href="#xo_attr" title="Attributes (xo_attr)">Section 3.2.2</a>) or "{e:}" fields (<a href="#e-modifier" title="The Encoding Modifier ({e:})">Section 2.2.2.4</a>) to make the data useful.</dd> <dt>Don't use an arbitrary number postfix</dt> <dd>What does "errors2" mean? No one will know. "errors‑after‑restart" would be a better choice. Think of your users, and think of the future. If you make "errors2", the next guy will happily make "errors3" and before you know it, someone will be asking what's the difference between errors37 and errors63.</dd> <dt>Be consistent, uniform, unsurprising, and predictable</dt> @@ -25838,10 +25988,10 @@ jQuery(function ($) { <a id="a-percent-sign-appearing-in-text-is-a-literal" href="#a-percent-sign-appearing-in-text-is-a-literal">'A percent sign appearing in text is a literal'</a> </h3> <p id="doc_section_8_2_1_p_1">The message "A percent sign appearing in text is a literal" can be caused by code like:</p> -<div id="doc_figure_u.133"></div> <pre> +<div id="doc_figure_u.140"></div> <pre> xo_emit("cost: %d", cost); </pre> <p id="doc_section_8_2_1_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.134"></div> <pre> +<div id="doc_figure_u.141"></div> <pre> xo_emit("{L:cost}: {:cost/%d}", cost); </pre> <p id="doc_section_8_2_1_p_5">This can be a bit surprising and could be a field that was not properly converted to a libxo-style format string.</p> </div> @@ -25852,10 +26002,10 @@ jQuery(function ($) { <a id="unknown-long-name-for-rolemodifier" href="#unknown-long-name-for-rolemodifier">'Unknown long name for role/modifier'</a> </h3> <p id="doc_section_8_2_2_p_1">The message "Unknown long name for role/modifier" can be caused by code like:</p> -<div id="doc_figure_u.135"></div> <pre> +<div id="doc_figure_u.142"></div> <pre> xo_emit("{,humanization:value}", value); </pre> <p id="doc_section_8_2_2_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.136"></div> <pre> +<div id="doc_figure_u.143"></div> <pre> xo_emit("{,humanize:value}", value); </pre> <p id="doc_section_8_2_2_p_5">The hn-* modifiers (hn-decimal, hn-space, hn-1000) are only valid for fields with the {h:} modifier.</p> </div> @@ -25867,10 +26017,10 @@ jQuery(function ($) { </h3> <p id="doc_section_8_2_3_p_1">The message "Last character before field definition is a field type" can be caused by code like:</p> <p id="doc_section_8_2_3_p_2">A common typo:</p> -<div id="doc_figure_u.137"></div> <pre> +<div id="doc_figure_u.144"></div> <pre> xo_emit("{T:Min} T{:Max}"); </pre> <p id="doc_section_8_2_3_p_4">This code should be replaced with code like:</p> -<div id="doc_figure_u.138"></div> <pre> +<div id="doc_figure_u.145"></div> <pre> xo_emit("{T:Min} {T:Max}"); </pre> <p id="doc_section_8_2_3_p_6">Twiddling the "{" and the field role is a common typo.</p> </div> @@ -25881,10 +26031,10 @@ jQuery(function ($) { <a id="encoding-format-uses-different-number-of-arguments" href="#encoding-format-uses-different-number-of-arguments">'Encoding format uses different number of arguments'</a> </h3> <p id="doc_section_8_2_4_p_1">The message "Encoding format uses different number of arguments" can be caused by code like:</p> -<div id="doc_figure_u.139"></div> <pre> +<div id="doc_figure_u.146"></div> <pre> xo_emit("{:name/%6.6s %%04d/%s}", name, number); </pre> <p id="doc_section_8_2_4_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.140"></div> <pre> +<div id="doc_figure_u.147"></div> <pre> xo_emit("{:name/%6.6s %04d/%s-%d}", name, number); </pre> <p id="doc_section_8_2_4_p_5">Both format should consume the same number of arguments off the stack</p> </div> @@ -25895,10 +26045,10 @@ jQuery(function ($) { <a id="only-one-field-role-can-be-used" href="#only-one-field-role-can-be-used">'Only one field role can be used'</a> </h3> <p id="doc_section_8_2_5_p_1">The message "Only one field role can be used" can be caused by code like:</p> -<div id="doc_figure_u.141"></div> <pre> +<div id="doc_figure_u.148"></div> <pre> xo_emit("{LT:Max}"); </pre> <p id="doc_section_8_2_5_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.142"></div> <pre> +<div id="doc_figure_u.149"></div> <pre> xo_emit("{T:Max}"); </pre> </div> <div class="content"> @@ -25908,10 +26058,10 @@ jQuery(function ($) { <a id="potential-missing-slash-after-c-d-n-l-or-t-with-format" href="#potential-missing-slash-after-c-d-n-l-or-t-with-format">'Potential missing slash after C, D, N, L, or T with format'</a> </h3> <p id="doc_section_8_2_6_p_1">The message "Potential missing slash after C, D, N, L, or T with format" can be caused by code like:</p> -<div id="doc_figure_u.143"></div> <pre> +<div id="doc_figure_u.150"></div> <pre> xo_emit("{T:%6.6s}\n", "Max"); </pre> <p id="doc_section_8_2_6_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.144"></div> <pre> +<div id="doc_figure_u.151"></div> <pre> xo_emit("{T:/%6.6s}\n", "Max"); </pre> <p id="doc_section_8_2_6_p_5">The "%6.6s" will be a literal, not a field format. While it's possibly valid, it's likely a missing "/".</p> </div> @@ -25922,7 +26072,7 @@ jQuery(function ($) { <a id="an-encoding-format-cannot-be-given-roles-dnlt" href="#an-encoding-format-cannot-be-given-roles-dnlt">'An encoding format cannot be given (roles: DNLT)'</a> </h3> <p id="doc_section_8_2_7_p_1">The message "An encoding format cannot be given (roles: DNLT)" can be caused by code like:</p> -<div id="doc_figure_u.145"></div> <pre> +<div id="doc_figure_u.152"></div> <pre> xo_emit("{T:Max//%s}", "Max"); </pre> <p id="doc_section_8_2_7_p_3">Fields with the C, D, N, L, and T roles are not emitted in the 'encoding' style (JSON, XML), so an encoding format would make no sense.</p> </div> @@ -25933,7 +26083,7 @@ jQuery(function ($) { <a id="format-cannot-be-given-when-content-is-present-roles-cdln" href="#format-cannot-be-given-when-content-is-present-roles-cdln">'Format cannot be given when content is present (roles: CDLN)'</a> </h3> <p id="doc_section_8_2_8_p_1">The message "Format cannot be given when content is present (roles: CDLN)" can be caused by code like:</p> -<div id="doc_figure_u.146"></div> <pre> +<div id="doc_figure_u.153"></div> <pre> xo_emit("{N:Max/%6.6s}", "Max"); </pre> <p id="doc_section_8_2_8_p_3">Fields with the C, D, L, or N roles can't have both static literal content ("{L:Label}") and a format ("{L:/%s}"). This error will also occur when the content has a backslash in it, like "{N:Type of I/O}"; backslashes should be escaped, like "{N:Type of I\\/O}". Note the double backslash, one for handling 'C' strings, and one for libxo.</p> </div> @@ -25944,10 +26094,10 @@ jQuery(function ($) { <a id="field-has-color-without-fg--or-bg--role-c" href="#field-has-color-without-fg--or-bg--role-c">'Field has color without fg- or bg- (role: C)'</a> </h3> <p id="doc_section_8_2_9_p_1">The message "Field has color without fg- or bg- (role: C)" can be caused by code like:</p> -<div id="doc_figure_u.147"></div> <pre> +<div id="doc_figure_u.154"></div> <pre> xo_emit("{C:green}{:foo}{C:}", x); </pre> <p id="doc_section_8_2_9_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.148"></div> <pre> +<div id="doc_figure_u.155"></div> <pre> xo_emit("{C:fg-green}{:foo}{C:}", x); </pre> <p id="doc_section_8_2_9_p_5">Colors must be prefixed by either "fg‑" or "bg‑".</p> </div> @@ -25958,10 +26108,10 @@ jQuery(function ($) { <a id="field-has-invalid-color-or-effect-role-c" href="#field-has-invalid-color-or-effect-role-c">'Field has invalid color or effect (role: C)'</a> </h3> <p id="doc_section_8_2_10_p_1">The message "Field has invalid color or effect (role: C)" can be caused by code like:</p> -<div id="doc_figure_u.149"></div> <pre> +<div id="doc_figure_u.156"></div> <pre> xo_emit("{C:fg-purple,bold}{:foo}{C:gween}", x); </pre> <p id="doc_section_8_2_10_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.150"></div> <pre> +<div id="doc_figure_u.157"></div> <pre> xo_emit("{C:fg-red,bold}{:foo}{C:fg-green}", x); </pre> <p id="doc_section_8_2_10_p_5">The list of colors and effects are limited. The set of colors includes default, black, red, green, yellow, blue, magenta, cyan, and white, which must be prefixed by either "fg‑" or "bg‑". Effects are limited to bold, no-bold, underline, no-underline, inverse, no-inverse, normal, and reset. Values must be separated by commas.</p> </div> @@ -25972,10 +26122,10 @@ jQuery(function ($) { <a id="field-has-humanize-modifier-but-no-format-string" href="#field-has-humanize-modifier-but-no-format-string">'Field has humanize modifier but no format string'</a> </h3> <p id="doc_section_8_2_11_p_1">The message "Field has humanize modifier but no format string" can be caused by code like:</p> -<div id="doc_figure_u.151"></div> <pre> +<div id="doc_figure_u.158"></div> <pre> xo_emit("{h:value}", value); </pre> <p id="doc_section_8_2_11_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.152"></div> <pre> +<div id="doc_figure_u.159"></div> <pre> xo_emit("{h:value/%d}", value); </pre> <p id="doc_section_8_2_11_p_5">Humanization is only value for numbers, which are not likely to use the default format ("%s").</p> </div> @@ -25986,10 +26136,10 @@ jQuery(function ($) { <a id="field-has-hn--modifier-but-not-h-modifier" href="#field-has-hn--modifier-but-not-h-modifier">'Field has hn-* modifier but not 'h' modifier'</a> </h3> <p id="doc_section_8_2_12_p_1">The message "Field has hn-* modifier but not 'h' modifier" can be caused by code like:</p> -<div id="doc_figure_u.153"></div> <pre> +<div id="doc_figure_u.160"></div> <pre> xo_emit("{,hn-1000:value}", value); </pre> <p id="doc_section_8_2_12_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.154"></div> <pre> +<div id="doc_figure_u.161"></div> <pre> xo_emit("{h,hn-1000:value}", value); </pre> <p id="doc_section_8_2_12_p_5">The hn-* modifiers (hn-decimal, hn-space, hn-1000) are only valid for fields with the {h:} modifier.</p> </div> @@ -26000,10 +26150,10 @@ jQuery(function ($) { <a id="value-field-must-have-a-name-as-content" href="#value-field-must-have-a-name-as-content">'Value field must have a name (as content)")'</a> </h3> <p id="doc_section_8_2_13_p_1">The message "Value field must have a name (as content)")" can be caused by code like:</p> -<div id="doc_figure_u.155"></div> <pre> +<div id="doc_figure_u.162"></div> <pre> xo_emit("{:/%s}", "value"); </pre> <p id="doc_section_8_2_13_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.156"></div> <pre> +<div id="doc_figure_u.163"></div> <pre> xo_emit("{:tag-name/%s}", "value"); </pre> <p id="doc_section_8_2_13_p_5">The field name is used for XML and JSON encodings. These tags names are static and must appear directly in the field descriptor.</p> </div> @@ -26014,10 +26164,10 @@ jQuery(function ($) { <a id="use-hyphens-not-underscores-for-value-field-name" href="#use-hyphens-not-underscores-for-value-field-name">'Use hyphens, not underscores, for value field name'</a> </h3> <p id="doc_section_8_2_14_p_1">The message "Use hyphens, not underscores, for value field name" can be caused by code like:</p> -<div id="doc_figure_u.157"></div> <pre> +<div id="doc_figure_u.164"></div> <pre> xo_emit("{:no_under_scores}", "bad"); </pre> <p id="doc_section_8_2_14_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.158"></div> <pre> +<div id="doc_figure_u.165"></div> <pre> xo_emit("{:no-under-scores}", "bad"); </pre> <p id="doc_section_8_2_14_p_5">Use of hyphens is traditional in XML, and the XOF_UNDERSCORES flag can be used to generate underscores in JSON, if desired. But the raw field name should use hyphens.</p> </div> @@ -26028,10 +26178,10 @@ jQuery(function ($) { <a id="value-field-name-cannot-start-with-digit" href="#value-field-name-cannot-start-with-digit">'Value field name cannot start with digit'</a> </h3> <p id="doc_section_8_2_15_p_1">The message "Value field name cannot start with digit" can be caused by code like:</p> -<div id="doc_figure_u.159"></div> <pre> +<div id="doc_figure_u.166"></div> <pre> xo_emit("{:10-gig/}"); </pre> <p id="doc_section_8_2_15_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.160"></div> <pre> +<div id="doc_figure_u.167"></div> <pre> xo_emit("{:ten-gig/}"); </pre> <p id="doc_section_8_2_15_p_5">XML element names cannot start with a digit.</p> </div> @@ -26042,10 +26192,10 @@ jQuery(function ($) { <a id="value-field-name-should-be-lower-case" href="#value-field-name-should-be-lower-case">'Value field name should be lower case'</a> </h3> <p id="doc_section_8_2_16_p_1">The message "Value field name should be lower case" can be caused by code like:</p> -<div id="doc_figure_u.161"></div> <pre> +<div id="doc_figure_u.168"></div> <pre> xo_emit("{:WHY-ARE-YOU-SHOUTING}", "NO REASON"); </pre> <p id="doc_section_8_2_16_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.162"></div> <pre> +<div id="doc_figure_u.169"></div> <pre> xo_emit("{:why-are-you-shouting}", "no reason"); </pre> <p id="doc_section_8_2_16_p_5">Lower case is more civilized. Even TLAs should be lower case to avoid scenarios where the differences between "XPath" and "Xpath" drive your users crazy. Lower case rules the seas.</p> </div> @@ -26056,10 +26206,10 @@ jQuery(function ($) { <a id="value-field-name-should-be-longer-than-two-characters" href="#value-field-name-should-be-longer-than-two-characters">'Value field name should be longer than two characters'</a> </h3> <p id="doc_section_8_2_17_p_1">The message "Value field name should be longer than two characters" can be caused by code like:</p> -<div id="doc_figure_u.163"></div> <pre> +<div id="doc_figure_u.170"></div> <pre> xo_emit("{:x}", "mumble"); </pre> <p id="doc_section_8_2_17_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.164"></div> <pre> +<div id="doc_figure_u.171"></div> <pre> xo_emit("{:something-meaningful}", "mumble"); </pre> <p id="doc_section_8_2_17_p_5">Field names should be descriptive, and it's hard to be descriptive in less than two characters. Consider your users and try to make something more useful. Note that this error often occurs when the field type is placed after the colon ("{:T/%20s}"), instead of before it ("{T:/20s}").</p> </div> @@ -26070,10 +26220,10 @@ jQuery(function ($) { <a id="value-field-name-contains-invalid-character" href="#value-field-name-contains-invalid-character">'Value field name contains invalid character'</a> </h3> <p id="doc_section_8_2_18_p_1">The message "Value field name contains invalid character" can be caused by code like:</p> -<div id="doc_figure_u.165"></div> <pre> +<div id="doc_figure_u.172"></div> <pre> xo_emit("{:cost-in-$$/%u}", 15); </pre> <p id="doc_section_8_2_18_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.166"></div> <pre> +<div id="doc_figure_u.173"></div> <pre> xo_emit("{:cost-in-dollars/%u}", 15); </pre> <p id="doc_section_8_2_18_p_5">An invalid character is often a sign of a typo, like "{:]}" instead of "{]:}". Field names are restricted to lower-case characters, digits, and hyphens.</p> </div> @@ -26084,10 +26234,10 @@ jQuery(function ($) { <a id="decoration-field-contains-invalid-character" href="#decoration-field-contains-invalid-character">'decoration field contains invalid character'</a> </h3> <p id="doc_section_8_2_19_p_1">The message "decoration field contains invalid character" can be caused by code like:</p> -<div id="doc_figure_u.167"></div> <pre> +<div id="doc_figure_u.174"></div> <pre> xo_emit("{D:not good}"); </pre> <p id="doc_section_8_2_19_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.168"></div> <pre> +<div id="doc_figure_u.175"></div> <pre> xo_emit("{D:((}{:good}{D:))}", "yes"); </pre> <p id="doc_section_8_2_19_p_5">This is minor, but fields should use proper roles. Decoration fields are meant to hold punctuation and other characters used to decorate the content, typically to make it more readable to human readers.</p> </div> @@ -26098,10 +26248,10 @@ jQuery(function ($) { <a id="anchor-content-should-be-decimal-width" href="#anchor-content-should-be-decimal-width">'Anchor content should be decimal width'</a> </h3> <p id="doc_section_8_2_20_p_1">The message "Anchor content should be decimal width" can be caused by code like:</p> -<div id="doc_figure_u.169"></div> <pre> +<div id="doc_figure_u.176"></div> <pre> xo_emit("{[:mumble}"); </pre> <p id="doc_section_8_2_20_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.170"></div> <pre> +<div id="doc_figure_u.177"></div> <pre> xo_emit("{[:32}"); </pre> <p id="doc_section_8_2_20_p_5">Anchors need an integer value to specify the width of the set of anchored fields. The value can be positive (for left padding/right justification) or negative (for right padding/left justification) and can appear in either the start or stop anchor field descriptor.</p> </div> @@ -26112,10 +26262,10 @@ jQuery(function ($) { <a id="anchor-format-should-be-d" href="#anchor-format-should-be-d">'Anchor format should be "%d"'</a> </h3> <p id="doc_section_8_2_21_p_1">The message "Anchor format should be "%d"" can be caused by code like:</p> -<div id="doc_figure_u.171"></div> <pre> +<div id="doc_figure_u.178"></div> <pre> xo_emit("{[:/%s}"); </pre> <p id="doc_section_8_2_21_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.172"></div> <pre> +<div id="doc_figure_u.179"></div> <pre> xo_emit("{[:/%d}"); </pre> <p id="doc_section_8_2_21_p_5">Anchors only grok integer values, and if the value is not static, if must be in an 'int' argument, represented by the "%d" format. Anything else is an error.</p> </div> @@ -26126,10 +26276,10 @@ jQuery(function ($) { <a id="anchor-cannot-have-both-format-and-encoding-format" href="#anchor-cannot-have-both-format-and-encoding-format">'Anchor cannot have both format and encoding format")'</a> </h3> <p id="doc_section_8_2_22_p_1">The message "Anchor cannot have both format and encoding format")" can be caused by code like:</p> -<div id="doc_figure_u.173"></div> <pre> +<div id="doc_figure_u.180"></div> <pre> xo_emit("{[:32/%d}"); </pre> <p id="doc_section_8_2_22_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.174"></div> <pre> +<div id="doc_figure_u.181"></div> <pre> xo_emit("{[:32}"); </pre> <p id="doc_section_8_2_22_p_5">Anchors can have a static value or argument for the width, but cannot have both.</p> </div> @@ -26140,10 +26290,10 @@ jQuery(function ($) { <a id="max-width-only-valid-for-strings" href="#max-width-only-valid-for-strings">'Max width only valid for strings'</a> </h3> <p id="doc_section_8_2_23_p_1">The message "Max width only valid for strings" can be caused by code like:</p> -<div id="doc_figure_u.175"></div> <pre> +<div id="doc_figure_u.182"></div> <pre> xo_emit("{:tag/%2.4.6d}", 55); </pre> <p id="doc_section_8_2_23_p_3">This code should be replaced with code like:</p> -<div id="doc_figure_u.176"></div> <pre> +<div id="doc_figure_u.183"></div> <pre> xo_emit("{:tag/%2.6d}", 55); </pre> <p id="doc_section_8_2_23_p_5">libxo allows a true 'max width' in addition to the traditional printf-style 'max number of bytes to use for input'. But this is supported only for string values, since it makes no sense for non-strings. This error may occur from a typo, like "{:tag/%6..6d}" where only one period should be used.</p> </div> @@ -26183,7 +26333,7 @@ jQuery(function ($) { <p id="doc_section_9_2_p_1">libxo is open source, under a new BSD license. Source code is available on github, as are recent releases. To get the most current release, please visit:</p> <p id="doc_section_9_2_p_2"> <a href="https://github.com/Juniper/libxo/releases">https://github.com/Juniper/libxo/releases</a></p> <p id="doc_section_9_2_p_3">After downloading and untarring the source code, building involves the following steps:</p> -<div id="doc_figure_u.177"></div> <pre> +<div id="doc_figure_u.184"></div> <pre> sh bin/setup.sh cd build ../configure @@ -26192,7 +26342,7 @@ jQuery(function ($) { sudo make install </pre> <p id="doc_section_9_2_p_5">libxo uses a distinct "build" directory to keep generated files separated from source files.</p> <p id="doc_section_9_2_p_6">Use "../configure --help" to display available configuration options, which include the following:</p> -<div id="doc_figure_u.178"></div> <pre> +<div id="doc_figure_u.185"></div> <pre> --enable-warnings Turn on compiler warnings --enable-debug Turn on debugging --enable-text-only Turn on text-only rendering @@ -26212,7 +26362,7 @@ jQuery(function ($) { <a href="#doc_section_9_3">9.3</a> </div> <a id="howto-convert-command-line-applications" href="#howto-convert-command-line-applications">Howto: Convert command line applications</a> </h2> -<div id="doc_figure_u.179"></div> <pre> +<div id="doc_figure_u.186"></div> <pre> How do I convert an existing command line application? </pre> <p id="doc_section_9_3_p_2">There are three basic steps for converting command line application to use libxo.</p> <p id="doc_section_9_3_p_3"> </p> @@ -26236,10 +26386,10 @@ jQuery(function ($) { <a id="setting-up-the-context" href="#setting-up-the-context">Setting up the context</a> </h3> <p id="doc_section_9_3_1_p_1">To use libxo, you'll need to include the "xo.h" header file in your source code files:</p> -<div id="doc_figure_u.180"></div> <pre> +<div id="doc_figure_u.187"></div> <pre> #include <libxo/xo.h> </pre> <p id="doc_section_9_3_1_p_3">In your main() function, you'll need to call xo_parse_args to handling argument parsing (<a href="#xo_parse_args" title="Parsing Command-line Arguments (xo_parse_args)">Section 3.4.1</a>). This function removes libxo-specific arguments the program's argv and returns either the number of remaining arguments or -1 to indicate an error.</p> -<div id="doc_figure_u.181"></div> <pre> +<div id="doc_figure_u.188"></div> <pre> int main (int argc, char **argv) { argc = xo_parse_args(argc, argv); @@ -26247,8 +26397,8 @@ jQuery(function ($) { return argc; .... } - </pre> <p id="doc_section_9_3_1_p_5">At the bottom of your main(), you'll need to call xo_finish() to complete output processing for the default handle (<a href="#handles" title="Handles">Section 2.5</a>). libxo provides the xo_finish_atexit function that is suitable for use with the atexit(3) function.</p> -<div id="doc_figure_u.182"></div> <pre> + </pre> <p id="doc_section_9_3_1_p_5">At the bottom of your main(), you'll need to call xo_finish() to complete output processing for the default handle (<a href="#handles" title="Handles">Section 3.1</a>). libxo provides the xo_finish_atexit function that is suitable for use with the atexit(3) function.</p> +<div id="doc_figure_u.189"></div> <pre> atexit(xo_finish_atexit); </pre> </div> <div class="content"> @@ -26258,20 +26408,20 @@ jQuery(function ($) { <a id="converting-printf-calls" href="#converting-printf-calls">Converting printf Calls</a> </h3> <p id="doc_section_9_3_2_p_1">The second task is inspecting code for printf(3) calls and replacing them with xo_emit() calls. The format strings are similar in task, but libxo format strings wrap output fields in braces. The following two calls produce identical text output:</p> -<div id="doc_figure_u.183"></div> <pre> +<div id="doc_figure_u.190"></div> <pre> printf("There are %d %s events\n", count, etype); xo_emit("There are {:count/%d} {:event} events\n", count, etype); </pre> <p id="doc_section_9_3_2_p_3">"count" and "event" are used as names for JSON and XML output. The "count" field uses the format "%d" and "event" uses the default "%s" format. Both are "value" roles, which is the default role.</p> <p id="doc_section_9_3_2_p_4">Since text outside of output fields is passed verbatim, other roles are less important, but their proper use can help make output more useful. The "note" and "label" roles allow HTML output to recognize the relationship between text and the associated values, allowing appropriate "hover" and "onclick" behavior. Using the "units" role allows the presentation layer to perform conversions when needed. The "warning" and "error" roles allows use of color and font to draw attention to warnings. The "padding" role makes the use of vital whitespace more clear (<a href="#padding-role" title="The Padding Role ({P:})">Section 2.2.1.6</a>).</p> <p id="doc_section_9_3_2_p_5">The "title" role indicates the headings of table and sections. This allows HTML output to use CSS to make this relationship more obvious.</p> -<div id="doc_figure_u.184"></div> <pre> +<div id="doc_figure_u.191"></div> <pre> printf("Statistics:\n"); xo_emit("{T:Statistics}:\n"); </pre> <p id="doc_section_9_3_2_p_7">The "color" roles controls foreground and background colors, as well as effects like bold and underline (see <a href="#color-role" title="The Color Role ({C:})">Section 2.2.1.1</a>).</p> -<div id="doc_figure_u.185"></div> <pre> +<div id="doc_figure_u.192"></div> <pre> xo_emit("{C:bold}required{C:}\n"); </pre> <p id="doc_section_9_3_2_p_9">Finally, the start- and stop-anchor roles allow justification and padding over multiple fields (see <a href="#anchor-role" title="The Anchor Roles ({[:} and {]:})">Section 2.2.1.10</a>).</p> -<div id="doc_figure_u.186"></div> <pre> +<div id="doc_figure_u.193"></div> <pre> snprintf(buf, sizeof(buf), "(%u/%u/%u)", min, ave, max); printf("%30s", buf); @@ -26285,7 +26435,7 @@ jQuery(function ($) { <a id="creating-hierarchy" href="#creating-hierarchy">Creating Hierarchy</a> </h3> <p id="doc_section_9_3_3_p_1">Text output doesn't have any sort of hierarchy, but XML and JSON require this. Typically applications use indentation to represent these relationship:</p> -<div id="doc_figure_u.187"></div> <pre> +<div id="doc_figure_u.194"></div> <pre> printf("table %d\n", tnum); for (i = 0; i < tmax; i++) { printf(" %s %d\n", table[i].name, table[i].size); @@ -26303,7 +26453,7 @@ jQuery(function ($) { </pre> <p id="doc_section_9_3_3_p_3">The open and close list functions are used before and after the list, and the open and close instance functions are used before and after each instance with in the list.</p> <p id="doc_section_9_3_3_p_4">Typically these developer looks for a "for" loop as an indication of where to put these calls.</p> <p id="doc_section_9_3_3_p_5">In addition, the open and close container functions allow for organization levels of hierarchy.</p> -<div id="doc_figure_u.188"></div> <pre> +<div id="doc_figure_u.195"></div> <pre> printf("Paging information:\n"); printf(" Free: %lu\n", free); printf(" Active: %lu\n", active); @@ -26322,7 +26472,7 @@ jQuery(function ($) { <a id="converting-error-functions" href="#converting-error-functions">Converting Error Functions</a> </h3> <p id="doc_section_9_3_4_p_1">libxo provides variants of the standard error and warning functions, err(3) and warn(3). There are two variants, one for putting the errors on standard error, and the other writes the errors and warnings to the handle using the appropriate encoding style:</p> -<div id="doc_figure_u.189"></div> <pre> +<div id="doc_figure_u.196"></div> <pre> err(1, "cannot open output file: %s", file); xo_err(1, "cannot open output file: %s", file); @@ -26340,12 +26490,12 @@ jQuery(function ($) { <a href="#doc_section_9_5">9.5</a> </div> <a id="howto-i18n" href="#howto-i18n">Howto: Internationalization (i18n)</a> </h2> -<div id="doc_figure_u.190"></div> <pre> +<div id="doc_figure_u.197"></div> <pre> How do I use libxo to support internationalization? </pre> <p id="doc_section_9_5_p_2">libxo allows format and field strings to be used a keys into message catalogs to enable translation into a user's native language by invoking the standard gettext(3) functions.</p> <p id="doc_section_9_5_p_3">gettext setup is a bit complicated: text strings are extracted from source files into "portable object template" (.pot) files using the "xgettext" command. For each language, this template file is used as the source for a message catalog in the "portable object" (.po) format, which are translated by hand and compiled into "machine object" (.mo) files using the "msgfmt" command. The .mo files are then typically installed in the /usr/share/locale or /opt/local/share/locale directories. At run time, the user's language settings are used to select a .mo file which is searched for matching messages. Text strings in the source code are used as keys to look up the native language strings in the .mo file.</p> <p id="doc_section_9_5_p_4">Since the xo_emit format string is used as the key into the message catalog, libxo removes unimportant field formatting and modifiers from the format string before use so that minor formatting changes will not impact the expensive translation process. We don't want a developer change such as changing "/%06d" to "/%08d" to force hand inspection of all .po files. The simplified version can be generated for a single message using the "xopo -s <text>" command, or an entire .pot can be translated using the "xopo -f <input> -o <output>" command.</p> -<div id="doc_figure_u.191"></div> <pre> +<div id="doc_figure_u.198"></div> <pre> EXAMPLE: % xopo -s "There are {:count/%u} {:event/%.6s} events\n" There are {:count} {:event} events\n @@ -26378,7 +26528,7 @@ jQuery(function ($) { sudo cp po/my_lang/LC_MESSAGES/foo.mo \ /opt/local/share/locale/my_lang/LC_MESSAGE/ </pre> <p id="doc_section_9_5_p_6">Once these steps are complete, you can use the "gettext" command to test the message catalog:</p> -<div id="doc_figure_u.192"></div> <pre> +<div id="doc_figure_u.199"></div> <pre> gettext -d foo -e "some text" </pre> <p id="doc_section_9_5_p_8">Section Contents: </p> <ul><li><a href="#i18n-and-xo_emit" title="i18n and xo_emit">Section 9.5.1</a></li></ul> @@ -26396,7 +26546,7 @@ jQuery(function ($) { <li>The "{p:}" modifier looks for a pluralized version of the field.</li> </ul> <p id="doc_section_9_5_1_p_3">Together these three flags allows a single function call to give native language support, as well as libxo's normal XML, JSON, and HTML support.</p> -<div id="doc_figure_u.193"></div> <pre> +<div id="doc_figure_u.200"></div> <pre> printf(gettext("Received %zu %s from {g:server} server\n"), counter, ngettext("byte", "bytes", counter), gettext("web")); @@ -26404,17 +26554,17 @@ jQuery(function ($) { xo_emit("{G:}Received {:received/%zu} {Ngp:byte,bytes} " "from {g:server} server\n", counter, "web"); </pre> <p id="doc_section_9_5_1_p_5">libxo will see the "{G:}" role and will first simplify the format string, removing field formats and modifiers.</p> -<div id="doc_figure_u.194"></div> <pre> +<div id="doc_figure_u.201"></div> <pre> "Received {:received} {N:byte,bytes} from {:server} server\n" </pre> <p id="doc_section_9_5_1_p_7">libxo calls gettext(3) with that string to get a localized version. If your language were Pig Latin, the result might look like:</p> -<div id="doc_figure_u.195"></div> <pre> +<div id="doc_figure_u.202"></div> <pre> "Eceivedray {:received} {N:byte,bytes} omfray " "{:server} erversay\n" </pre> <p id="doc_section_9_5_1_p_9">Note the field names do not change and they should not be translated. The contents of the note ("byte,bytes") should also not be translated, since the "g" modifier will need the untranslated value as the key for the message catalog.</p> <p id="doc_section_9_5_1_p_10">The field "{g:server}" requests the rendered value of the field be translated using gettext(3). In this example, "web" would be used.</p> <p id="doc_section_9_5_1_p_11">The field "{Ngp:byte,bytes}" shows an example of plural form using the "p" modifier with the "g" modifier. The base singular and plural forms appear inside the field, separated by a comma. At run time, libxo uses the previous field's numeric value to decide which form to use by calling ngettext(3).</p> <p id="doc_section_9_5_1_p_12">If a domain name is needed, it can be supplied as the content of the {G:} role. Domain names remain in use throughout the format string until cleared with another domain name.</p> -<div id="doc_figure_u.196"></div> <pre> +<div id="doc_figure_u.203"></div> <pre> printf(dgettext("dns", "Host %s not found: %d(%s)\n"), name, errno, dgettext("strerror", strerror(errno))); @@ -26439,7 +26589,7 @@ jQuery(function ($) { <a id="unit-test" href="#unit-test">Unit Test</a> </h2> <p id="doc_section_10_1_p_1">Here is the unit test example:</p> -<div id="doc_figure_u.197"></div> <pre> +<div id="doc_figure_u.204"></div> <pre> int main (int argc, char **argv) { @@ -26532,7 +26682,7 @@ jQuery(function ($) { return 0; } </pre> <p id="doc_section_10_1_p_3">Text output:</p> -<div id="doc_figure_u.198"></div> <pre> +<div id="doc_figure_u.205"></div> <pre> % ./testxo --libxo text Item 'gum': Total sold: 1412.0 @@ -26565,7 +26715,7 @@ jQuery(function ($) { On order: 1 SKU: GRO-000-533 </pre> <p id="doc_section_10_1_p_5">JSON output:</p> -<div id="doc_figure_u.199"></div> <pre> +<div id="doc_figure_u.206"></div> <pre> % ./testxo --libxo json,pretty "top": { "data": { @@ -26620,7 +26770,7 @@ jQuery(function ($) { } } </pre> <p id="doc_section_10_1_p_7">XML output:</p> -<div id="doc_figure_u.200"></div> <pre> +<div id="doc_figure_u.207"></div> <pre> % ./testxo --libxo pretty,xml <top> <data> @@ -26671,7 +26821,7 @@ jQuery(function ($) { </data> </top> </pre> <p id="doc_section_10_1_p_9">HMTL output:</p> -<div id="doc_figure_u.201"></div> <pre> +<div id="doc_figure_u.208"></div> <pre> % ./testxo --libxo pretty,html <div class="line"> <div class="label">Item</div> @@ -26866,7 +27016,7 @@ jQuery(function ($) { <div class="data" data-tag="sku">GRO-000-533</div> </div> </pre> <p id="doc_section_10_1_p_11">HTML output with xpath and info flags:</p> -<div id="doc_figure_u.202"></div> <pre> +<div id="doc_figure_u.209"></div> <pre> % ./testxo --libxo pretty,html,xpath,info <div class="line"> <div class="label">Item</div> diff --git a/contrib/libxo/doc/libxo.txt b/contrib/libxo/doc/libxo.txt index 1e7acc7..ba63702 100644 --- a/contrib/libxo/doc/libxo.txt +++ b/contrib/libxo/doc/libxo.txt @@ -699,25 +699,26 @@ XOF_WARN is set, a warning will be generated. Field modifiers are flags which modify the way content emitted for particular output styles: -|---+---------------+-------------------------------------------------| -| M | Name | Description | -|---+---------------+-------------------------------------------------| -| c | colon | A colon (":") is appended after the label | -| d | display | Only emit field for display styles (text/HTML) | -| e | encoding | Only emit for encoding styles (XML/JSON) | -| g | gettext | Call gettext on field's render content | -| h | humanize (hn) | Format large numbers in human-readable style | -| | hn-space | Humanize: Place space between numeric and unit | -| | hn-decimal | Humanize: Add a decimal digit, if number < 10 | -| | hn-1000 | Humanize: Use 1000 as divisor instead of 1024 | -| k | key | Field is a key, suitable for XPath predicates | -| l | leaf-list | Field is a leaf-list | -| n | no-quotes | Do not quote the field when using JSON style | -| p | plural | Gettext: Use comma-separated plural form | -| q | quotes | Quote the field when using JSON style | -| t | trim | Trim leading and trailing whitespace | -| w | white | A blank (" ") is appended after the label | -|---+---------------+-------------------------------------------------| +|---+---------------+--------------------------------------------------| +| M | Name | Description | +|---+---------------+--------------------------------------------------| +| a | argument | The content appears as a 'const char *' argument | +| c | colon | A colon (":") is appended after the label | +| d | display | Only emit field for display styles (text/HTML) | +| e | encoding | Only emit for encoding styles (XML/JSON) | +| g | gettext | Call gettext on field's render content | +| h | humanize (hn) | Format large numbers in human-readable style | +| | hn-space | Humanize: Place space between numeric and unit | +| | hn-decimal | Humanize: Add a decimal digit, if number < 10 | +| | hn-1000 | Humanize: Use 1000 as divisor instead of 1024 | +| k | key | Field is a key, suitable for XPath predicates | +| l | leaf-list | Field is a leaf-list | +| n | no-quotes | Do not quote the field when using JSON style | +| p | plural | Gettext: Use comma-separated plural form | +| q | quotes | Quote the field when using JSON style | +| t | trim | Trim leading and trailing whitespace | +| w | white | A blank (" ") is appended after the label | +|---+---------------+--------------------------------------------------| Roles and modifiers can also use more verbose names, when preceeded by a comma. For example, the modifier string "Lwc" (or "L,white,colon") @@ -727,6 +728,27 @@ modifier string "Vkq" (or ":key,quote") means the field has a value role (the default role), that it is a key for the current instance, and that the value should be quoted when encoded for JSON. +**** The Argument Modifier ({a:}) + +The argument modifier indicates that the content of the field +descriptor will be placed as a UTF-8 string (const char *) argument +within the xo_emit parameters. + + EXAMPLE: + xo_emit("{La:} {a:}\n", "Label text", "label", "value"); + TEXT: + Label text value + JSON: + "label": "value" + XML: + <label>value</label> + +The argument modifier allows field names for value fields to be passed +on the stack, avoiding the need to build a field descriptor using +snprintf. For many field roles, the argument modifier is not needed, +since those roles have specific mechanisms for arguments, such as +"{C:fg-%s}". + **** The Colon Modifier ({c:}) The colon modifier appends a single colon to the data value: @@ -907,6 +929,21 @@ needed, but often this needs to be controlled by the caller. JSON: "year": "2014" +The heuristic is based on the format; if the format uses any of the +following conversion specifiers, then no quotes are used: + + d i o u x X D O U e E f F g G a A c C p + +**** The Trim Modifier ({t:}) + +The trim modifier removes any leading or trailing whitespace from +the value. + + EXAMPLE: + xo_emit("{t:description}", " some input "); + JSON: + "description": "some input" + **** The White Space Modifier ({w:}) The white space modifier appends a single space to the data value: @@ -1029,6 +1066,24 @@ LANG, or LC_ALL environment varibles. The first of this list of variables is used and if none of the variables are set, the locale defaults to "UTF-8". +libxo will convert these arguments as needed to either UTF-8 (for XML, +JSON, and HTML styles) or locale-based strings for display in text +style. + + xo_emit("Alll strings are utf-8 content {:tag/%ls}", + L"except for wide strings"); + +"%S" is equivalent to "%ls". + +|--------+-----------------+-------------------------------| +| Format | Argument Type | Argument Contents | +|--------+-----------------+-------------------------------| +| %s | const char * | UTF-8 string | +| %S | const char * | UTF-8 string (alias for '%s') | +| %ls | const wchar_t * | Wide character UNICODE string | +| %hs | const char * | locale-based string | +|--------+-----------------+-------------------------------| + For example, a function is passed a locale-base name, a hat size, and a time value. The hat size is formatted in a UTF-8 (ASCII) string, and the time value is formatted into a wchar_t string. @@ -1163,6 +1218,53 @@ variants might be wise. | xo_emit_errc | xo_emit_errc_p | |------------------+------------------------| +*** Retaining Parsed Format Information @retain@ + +libxo can retain the parsed internal information related to the given +format string, allowing subsequent xo_emit calls, the retained +information is used, avoiding repetitive parsing of the format string. + + SYNTAX: + int xo_emit_f(xo_emit_flags_t flags, const char fmt, ...); + EXAMPLE: + xo_emit_f(XOEF_RETAIN, "{:some/%02d}{:thing/%-6s}{:fancy}\n", + some, thing, fancy); + +To retain parsed format information, use the XOEF_RETAIN flag to the +xo_emit_f() function. A complete set of xo_emit_f functions exist to +match all the xo_emit function signatures (with handles, varadic +argument, and printf-like flags): + +|------------------+------------------------| +| Function | Flags Equivalent | +|------------------+------------------------| +| xo_emit_hv | xo_emit_hvf | +| xo_emit_h | xo_emit_hf | +| xo_emit | xo_emit_f | +| xo_emit_hvp | xo_emit_hvfp | +| xo_emit_hp | xo_emit_hfp | +| xo_emit_p | xo_emit_fp | +|------------------+------------------------| + +The format string must be immutable across multiple calls to xo_emit_f(), +since the library retains the string. Typically this is done by using +static constant strings, such as string literals. If the string is not +immutable, the XOEF_RETAIN flag must not be used. + +The functions xo_retain_clear() and xo_retain_clear_all() release +internal information on either a single format string or all format +strings, respectively. Neither is required, but the library will +retain this information until it is cleared or the process exits. + + const char *fmt = "{:name} {:count/%d}\n"; + for (i = 0; i < 1000; i++) { + xo_open_instance("item"); + xo_emit_f(XOEF_RETAIN, fmt, name[i], count[i]); + } + xo_retain_clear(fmt); + +The retained information is kept as thread-specific data. + *** Example In this example, the value for the number of items in stock is emitted: @@ -1196,46 +1298,6 @@ penultimate line to: data-type="number" data-help="Number of items in stock">144</div> -** Command-line Arguments - -libxo uses command line options to trigger rendering behavior. The -following options are recognised: - -- --libxo <options> -- --libxo=<options> -- --libxo:<brief-options> - -Options is a comma-separated list of tokens that correspond to output -styles, flags, or features: - -|-------------+-------------------------------------------------------| -| Token | Action | -|-------------+-------------------------------------------------------| -| color | Enable colors/effects for display styles (TEXT, HTML) | -| dtrt | Enable "Do The Right Thing" mode | -| html | Emit HTML output | -| indent=xx | Set the indentation level | -| info | Add info attributes (HTML) | -| json | Emit JSON output | -| keys | Emit the key attribute for keys (XML) | -| log-gettext | Log (via stderr) each gettext(3) string lookup | -| log-syslog | Log (via stderr) each syslog message (via xo_syslog) | -| no-humanize | Ignore the {h:} modifier (TEXT, HTML) | -| no-locale | Do not initialize the locale setting | -| no-top | Do not emit a top set of braces (JSON) | -| not-first | Pretend the 1st output item was not 1st (JSON) | -| pretty | Emit pretty-printed output | -| text | Emit TEXT output | -| underscores | Replace XML-friendly "-"s with JSON friendly "_"s e | -| units | Add the 'units' (XML) or 'data-units (HTML) attribute | -| warn | Emit warnings when libxo detects bad calls | -| warn-xml | Emit warnings in XML | -| xml | Emit XML output | -| xpath | Add XPath expressions (HTML) | -|-------------+-------------------------------------------------------| - -The brief options are detailed in ^LIBXO_OPTIONS^. - ** Representing Hierarchy For XML and JSON, individual fields appear inside hierarchies which @@ -1382,68 +1444,89 @@ properly. xo_close_marker("fish-guts"); } -** Handles @handles@ - -libxo uses "handles" to control its rendering functionality. The -handle contains state and buffered data, as well as callback functions -to process data. - -A default handle is used when a NULL is passed to functions accepting -a handle. This handle is initialized to write its data to stdout -using the default style of text (XO_STYLE_TEXT). - -For the convenience of callers, the libxo library includes handle-less -functions that implicitly use the default handle. Any function that -takes a handle will use the default handle is a value of NULL is -passed in place of a valid handle. - -For example, the following are equivalent: - - xo_emit("test"); - xo_emit_h(NULL, "test"); +** Command-line Arguments -Handles are created using xo_create() and destroy using xo_destroy(). +libxo uses command line options to trigger rendering behavior. The +following options are recognised: -** UTF-8 +- --libxo <options> +- --libxo=<options> +- --libxo:<brief-options> -All strings for libxo must be UTF-8. libxo will handle turning them -into locale-based strings for display to the user. +Programs using libxo are expecting to call the xo_parse_args function +to parse these arguments. See ^xo_parse_args^ for details. -The only exception is argument formatted using the "%ls" format, which -require a wide character string (wchar_t *) as input. libxo will -convert these arguments as needed to either UTF-8 (for XML, JSON, and -HTML styles) or locale-based strings for display in text style. +Options is a comma-separated list of tokens that correspond to output +styles, flags, or features: - xo_emit("Alll strings are utf-8 content {:tag/%ls}", - L"except for wide strings"); +|-------------+-------------------------------------------------------| +| Token | Action | +|-------------+-------------------------------------------------------| +| color | Enable colors/effects for display styles (TEXT, HTML) | +| dtrt | Enable "Do The Right Thing" mode | +| html | Emit HTML output | +| indent=xx | Set the indentation level | +| info | Add info attributes (HTML) | +| json | Emit JSON output | +| keys | Emit the key attribute for keys (XML) | +| log-gettext | Log (via stderr) each gettext(3) string lookup | +| log-syslog | Log (via stderr) each syslog message (via xo_syslog) | +| no-humanize | Ignore the {h:} modifier (TEXT, HTML) | +| no-locale | Do not initialize the locale setting | +| no-retain | Prevent retaining formatting information | +| no-top | Do not emit a top set of braces (JSON) | +| not-first | Pretend the 1st output item was not 1st (JSON) | +| pretty | Emit pretty-printed output | +| retain | Force retaining formatting information | +| text | Emit TEXT output | +| underscores | Replace XML-friendly "-"s with JSON friendly "_"s e | +| units | Add the 'units' (XML) or 'data-units (HTML) attribute | +| warn | Emit warnings when libxo detects bad calls | +| warn-xml | Emit warnings in XML | +| xml | Emit XML output | +| xpath | Add XPath expressions (HTML) | +|-------------+-------------------------------------------------------| -"%S" is equivalent to "%ls". +The brief options are detailed in ^LIBXO_OPTIONS^. * The libxo API This section gives details about the functions in libxo, how to call them, and the actions they perform. -** Handles +** Handles @handles@ + +libxo uses "handles" to control its rendering functionality. The +handle contains state and buffered data, as well as callback functions +to process data. Handles give an abstraction for libxo that encapsulates the state of a stream of output. Handles have the data type "xo_handle_t" and are opaque to the caller. The library has a default handle that is automatically initialized. -By default, this handle will send text style output to standard output. -The xo_set_style and xo_set_flags functions can be used to change this -behavior. - -Many libxo functions take a handle as their first parameter; most that -do not use the default handle. Any function taking a handle can -be passed NULL to access the default handle. +By default, this handle will send text style output (XO_STYLE_TEXT) to +standard output. The xo_set_style and xo_set_flags functions can be +used to change this behavior. For the typical command that is generating output on standard output, there is no need to create an explicit handle, but they are available when needed, e.g., for daemons that generate multiple streams of output. +Many libxo functions take a handle as their first parameter; most that +do not use the default handle. Any function taking a handle can be +passed NULL to access the default handle. For the convenience of +callers, the libxo library includes handle-less functions that +implicitly use the default handle. + +For example, the following are equivalent: + + xo_emit("test"); + xo_emit_h(NULL, "test"); + +Handles are created using xo_create() and destroy using xo_destroy(). + *** xo_create A handle can be allocated using the xo_create() function: @@ -1653,11 +1736,34 @@ string, since an inappropriate cast can ruin your day. The vap argument to xo_emit_hv() points to a variable argument list that can be used to retrieve arguments via va_arg(). +*** Single Field Emitting Functions (xo_emit_field) @xo_emit_field@ + +The following functions can also make output, but only make a single +field at a time: + + int xo_emit_field_hv (xo_handle_t *xop, const char *rolmod, + const char *contents, const char *fmt, + const char *efmt, va_list vap); + + int xo_emit_field_h (xo_handle_t *xop, const char *rolmod, + const char *contents, const char *fmt, + const char *efmt, ...); + + int xo_emit_field (const char *rolmod, const char *contents, + const char *fmt, const char *efmt, ...); + +These functions are intended to avoid the scenario where one +would otherwise need to compose a format descriptors using +snprintf(). The individual parts of the format descriptor are +passed in distinctly. + + xo_emit("T", "Host name is ", NULL, NULL); + xo_emit("V", "host-name", NULL, NULL, host-name); + *** Attributes (xo_attr) @xo_attr@ The xo_attr() function emits attributes for the XML output style. - int xo_attr (const char *name, const char *fmt, ...); int xo_attr_h (xo_handle_t *xop, const char *name, const char *fmt, ...); @@ -2555,23 +2661,23 @@ In 2001, we added an XML API to the JUNOS operating system, which is built on top of FreeBSD. Eventually this API became standardized as the NETCONF API (RFC 6241). As part of this effort, we modified many FreeBSD utilities to emit XML, typically via a "-X" switch. The -results were mixed. The cost of maintaining this code, updating it +results were mixed. The cost of maintaining this code, updating it, and carrying it were non-trivial, and contributed to our expense (and the associated delay) with upgrading the version of FreeBSD on which each release of JUNOS is based. A recent (2014) effort within JUNOS aims at removing our modifications to the underlying FreeBSD code as a means of reducing the expense and -delay. JUNOS is structured to have system components generate XML -that is rendered by the CLI (think: login shell) into human-readable -text. This allows the API to use the same plumbing as the CLI, and -ensures that all components emit XML, and that it is emitted with -knowledge of the consumer of that XML, yielding an API that have no -incremental cost or feature delay. +delay in tracking HEAD. JUNOS is structured to have system components +generate XML that is rendered by the CLI (think: login shell) into +human-readable text. This allows the API to use the same plumbing as +the CLI, and ensures that all components emit XML, and that it is +emitted with knowledge of the consumer of that XML, yielding an API +that have no incremental cost or feature delay. libxo is an effort to mix the best aspects of the JUNOS strategy into FreeBSD in a seemless way, allowing commands to make printf-like -output calls without needing to care how the output is rendered. +output calls with a single code path. *** Did the complex semantics of format strings evolve over time? |