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Diffstat (limited to 'contrib/gperf/doc/gperf.1')
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1 files changed, 183 insertions, 19 deletions
diff --git a/contrib/gperf/doc/gperf.1 b/contrib/gperf/doc/gperf.1 index 1e4a2aa..dd425e0 100644 --- a/contrib/gperf/doc/gperf.1 +++ b/contrib/gperf/doc/gperf.1 @@ -1,23 +1,187 @@ -.TH GPERF 1 "March 7, 1998 -.UC 4 +.\" DO NOT MODIFY THIS FILE! It was generated by help2man 1.022. +.TH GPERF "1" "September 2000" "GNU gperf 2.7.2" FSF .SH NAME gperf \- generate a perfect hash function from a key set .SH SYNOPSIS -.B gperf -[ -.B \-adghijklnoprsStv -] [ -.I keyfile -] +.B gperf +[\fIOPTION\fR]... [\fIINPUT-FILE\fR] .SH DESCRIPTION - -\fIgperf\fP reads a set of ``keys'' from \fIkeyfile\fP (or, by -default, from the standard input) and attempts to find a non-minimal -perfect hashing function that recognizes a member of the key set in -constant, i.e., O(1), time. If such a function is found the program -generates a pair of \fIC\fP source code routines that perform the -hashing and table lookup. All generated code is directed to the -standard output. - -Please refer to the \fIgperf.texi\fP file for more information. -This file is distributed with \fIgperf\fP release. +GNU `gperf' generates perfect hash functions. +.PP +If a long option shows an argument as mandatory, then it is mandatory +for the equivalent short option also. +.SS "Input file interpretation:" +.TP +\fB\-e\fR, \fB\-\-delimiters\fR=\fIDELIMITER\-LIST\fR +Allow user to provide a string containing delimiters +used to separate keywords from their attributes. +Default is ",\en". +.TP +\fB\-t\fR, \fB\-\-struct\-type\fR +Allows the user to include a structured type +declaration for generated code. Any text before %% +is considered part of the type declaration. Key +words and additional fields may follow this, one +group of fields per line. +.SS "Language for the output code:" +.TP +\fB\-L\fR, \fB\-\-language\fR=\fILANGUAGE\-NAME\fR +Generates code in the specified language. Languages +handled are currently C++, ANSI-C, C, and KR-C. The +default is C. +.SS "Details in the output code:" +.TP +\fB\-K\fR, \fB\-\-slot\-name\fR=\fINAME\fR +Select name of the keyword component in the keyword +structure. +.TP +\fB\-F\fR, \fB\-\-initializer\-suffix\fR=\fIINITIALIZERS\fR +Initializers for additional components in the keyword +structure. +.TP +\fB\-H\fR, \fB\-\-hash\-fn\-name\fR=\fINAME\fR +Specify name of generated hash function. Default is +`hash'. +.TP +\fB\-N\fR, \fB\-\-lookup\-fn\-name\fR=\fINAME\fR +Specify name of generated lookup function. Default +name is `in_word_set'. +.TP +\fB\-Z\fR, \fB\-\-class\-name\fR=\fINAME\fR +Specify name of generated C++ class. Default name is +`Perfect_Hash'. +.TP +\fB\-7\fR, \fB\-\-seven\-bit\fR +Assume 7-bit characters. +.TP +\fB\-c\fR, \fB\-\-compare\-strncmp\fR +Generate comparison code using strncmp rather than +strcmp. +.TP +\fB\-C\fR, \fB\-\-readonly\-tables\fR +Make the contents of generated lookup tables +constant, i.e., readonly. +.TP +\fB\-E\fR, \fB\-\-enum\fR +Define constant values using an enum local to the +lookup function rather than with defines. +.TP +\fB\-I\fR, \fB\-\-includes\fR +Include the necessary system include file <string.h> +at the beginning of the code. +.TP +\fB\-G\fR, \fB\-\-global\fR +Generate the static table of keywords as a static +global variable, rather than hiding it inside of the +lookup function (which is the default behavior). +.TP +\fB\-W\fR, \fB\-\-word\-array\-name\fR=\fINAME\fR +Specify name of word list array. Default name is +`wordlist'. +.TP +\fB\-S\fR, \fB\-\-switch\fR=\fICOUNT\fR +Causes the generated C code to use a switch +statement scheme, rather than an array lookup table. +This can lead to a reduction in both time and space +requirements for some keyfiles. The COUNT argument +determines how many switch statements are generated. +A value of 1 generates 1 switch containing all the +elements, a value of 2 generates 2 tables with 1/2 +the elements in each table, etc. If COUNT is very +large, say 1000000, the generated C code does a +binary search. +.TP +\fB\-T\fR, \fB\-\-omit\-struct\-type\fR +Prevents the transfer of the type declaration to the +output file. Use this option if the type is already +defined elsewhere. +.SS "Algorithm employed by gperf:" +.TP +\fB\-k\fR, \fB\-\-key\-positions\fR=\fIKEYS\fR +Select the key positions used in the hash function. +The allowable choices range between 1-126, inclusive. +The positions are separated by commas, ranges may be +used, and key positions may occur in any order. +Also, the meta-character '*' causes the generated +hash function to consider ALL key positions, and $ +indicates the ``final character'' of a key, e.g., +$,1,2,4,6-10. +.TP +\fB\-l\fR, \fB\-\-compare\-strlen\fR +Compare key lengths before trying a string +comparison. This helps cut down on the number of +string comparisons made during the lookup. +.TP +\fB\-D\fR, \fB\-\-duplicates\fR +Handle keywords that hash to duplicate values. This +is useful for certain highly redundant keyword sets. +.TP +\fB\-f\fR, \fB\-\-fast\fR=\fIITERATIONS\fR +Generate the gen-perf.hash function ``fast''. This +decreases gperf's running time at the cost of +minimizing generated table size. The numeric +argument represents the number of times to iterate +when resolving a collision. `0' means ``iterate by +the number of keywords''. +.TP +\fB\-i\fR, \fB\-\-initial\-asso\fR=\fIN\fR +Provide an initial value for the associate values +array. Default is 0. Setting this value larger helps +inflate the size of the final table. +.TP +\fB\-j\fR, \fB\-\-jump\fR=\fIJUMP\-VALUE\fR +Affects the ``jump value'', i.e., how far to advance +the associated character value upon collisions. Must +be an odd number, default is 5. +.TP +\fB\-n\fR, \fB\-\-no\-strlen\fR +Do not include the length of the keyword when +computing the hash function. +.TP +\fB\-o\fR, \fB\-\-occurrence\-sort\fR +Reorders input keys by frequency of occurrence of +the key sets. This should decrease the search time +dramatically. +.TP +\fB\-r\fR, \fB\-\-random\fR +Utilizes randomness to initialize the associated +values table. +.TP +\fB\-s\fR, \fB\-\-size\-multiple\fR=\fIN\fR +Affects the size of the generated hash table. The +numeric argument N indicates ``how many times larger +or smaller'' the associated value range should be, +in relationship to the number of keys, e.g. a value +of 3 means ``allow the maximum associated value to +be about 3 times larger than the number of input +keys.'' Conversely, a value of \fB\-3\fR means ``make the +maximum associated value about 3 times smaller than +the number of input keys. A larger table should +decrease the time required for an unsuccessful +search, at the expense of extra table space. Default +value is 1. +.SS "Informative output:" +.TP +\fB\-h\fR, \fB\-\-help\fR +Print this message. +.TP +\fB\-v\fR, \fB\-\-version\fR +Print the gperf version number. +.TP +\fB\-d\fR, \fB\-\-debug\fR +Enables the debugging option (produces verbose +output to the standard error). +.SH "REPORTING BUGS" +Report bugs to <bug-gnu-utils@gnu.org>. +.SH "SEE ALSO" +The full documentation for +.B gperf +is maintained as a Texinfo manual. If the +.B info +and +.B gperf +programs are properly installed at your site, the command +.IP +.B info gperf +.PP +should give you access to the complete manual. |
