Import the [now] dual licensed version 3.5.4 of less. It is

distributed under your choice of the GPL or a BSD style license.

Reviewed by:	peter
Obtained from:	http://home.flash.net/~marknu/less/

1 files changed, 231 insertions, 0 deletions

diff --git a/contrib/less/tags.c b/contrib/less/tags.c
new file mode 100644
index 0000000..cf531a6
--- /dev/null
+++ b/contrib/less/tags.c
@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 1984-2000  Mark Nudelman
+ *
+ * You may distribute under the terms of either the GNU General Public
+ * License or the Less License, as specified in the README file.
+ *
+ * For more information about less, or for information on how to 
+ * contact the author, see the README file.
+ */
+
+
+#include "less.h"
+
+#define	WHITESP(c)	((c)==' ' || (c)=='\t')
+
+#if TAGS
+
+public char *tags = "tags";
+
+static char *tagfile;
+static char *tagpattern;
+static int taglinenum;
+static int tagendline;
+
+extern int linenums;
+extern int sigs;
+extern int jump_sline;
+
+/*
+ * Find a tag in the "tags" file.
+ * Sets "tagfile" to the name of the file containing the tag,
+ * and "tagpattern" to the search pattern which should be used
+ * to find the tag.
+ */
+	public void
+findtag(tag)
+	register char *tag;
+{
+	char *p;
+	char *q;
+	register FILE *f;
+	register int taglen;
+	int search_char;
+	int err;
+	char tline[TAGLINE_SIZE];
+
+	p = unquote_file(tags);
+	f = fopen(p, "r");
+	free(p);
+	if (f == NULL)
+	{
+		error("No tags file", NULL_PARG);
+		tagfile = NULL;
+		return;
+	}
+
+	taglen = strlen(tag);
+
+	/*
+	 * Search the tags file for the desired tag.
+	 */
+	while (fgets(tline, sizeof(tline), f) != NULL)
+	{
+		if (strncmp(tag, tline, taglen) != 0 || !WHITESP(tline[taglen]))
+			continue;
+
+		/*
+		 * Found it.
+		 * The line contains the tag, the filename and the
+		 * location in the file, separated by white space.
+		 * The location is either a decimal line number, 
+		 * or a search pattern surrounded by a pair of delimiters.
+		 * Parse the line and extract these parts.
+		 */
+		tagfile = tagpattern = NULL;
+		taglinenum = 0;
+
+		/*
+		 * Skip over the whitespace after the tag name.
+		 */
+		p = skipsp(tline+taglen);
+		if (*p == '\0')
+			/* File name is missing! */
+			continue;
+
+		/*
+		 * Save the file name.
+		 * Skip over the whitespace after the file name.
+		 */
+		tagfile = p;
+		while (!WHITESP(*p) && *p != '\0')
+			p++;
+		*p++ = '\0';
+		p = skipsp(p);
+		if (*p == '\0')
+			/* Pattern is missing! */
+			continue;
+		tagfile = save(tagfile);
+
+		/*
+		 * First see if it is a line number. 
+		 */
+		taglinenum = getnum(&p, 0, &err);
+		if (err)
+		{
+			/*
+			 * No, it must be a pattern.
+			 * Delete the initial "^" (if present) and 
+			 * the final "$" from the pattern.
+			 * Delete any backslash in the pattern.
+			 */
+			taglinenum = 0;
+			search_char = *p++;
+			if (*p == '^')
+				p++;
+			tagpattern = (char *) ecalloc(strlen(p)+1, sizeof(char));
+			q = tagpattern;
+			while (*p != search_char && *p != '\0')
+			{
+				if (*p == '\\')
+					p++;
+				*q++ = *p++;
+			}
+			tagendline = (q[-1] == '$');
+			if (tagendline)
+				q--;
+			*q = '\0';
+		}
+
+		fclose(f);
+		return;
+	}
+	fclose(f);
+	error("No such tag in tags file", NULL_PARG);
+	tagfile = NULL;
+}
+
+	public int
+edit_tagfile()
+{
+	int r;
+
+	if (tagfile == NULL)
+		return (1);
+	r = edit(tagfile);
+	free(tagfile);
+	tagfile = NULL;
+	return (r);
+}
+
+/*
+ * Search for a tag.
+ * This is a stripped-down version of search().
+ * We don't use search() for several reasons:
+ *   -	We don't want to blow away any search string we may have saved.
+ *   -	The various regular-expression functions (from different systems:
+ *	regcmp vs. re_comp) behave differently in the presence of 
+ *	parentheses (which are almost always found in a tag).
+ */
+	public POSITION
+tagsearch()
+{
+	POSITION pos, linepos;
+	int linenum;
+	int len;
+	char *line;
+
+	/*
+	 * If we have the line number of the tag instead of the pattern,
+	 * just use find_pos.
+	 */
+	if (taglinenum)
+		return (find_pos(taglinenum));
+
+	pos = ch_zero();
+	linenum = find_linenum(pos);
+
+	for (;;)
+	{
+		/*
+		 * Get lines until we find a matching one or 
+		 * until we hit end-of-file.
+		 */
+		if (ABORT_SIGS())
+			return (NULL_POSITION);
+
+		/*
+		 * Read the next line, and save the 
+		 * starting position of that line in linepos.
+		 */
+		linepos = pos;
+		pos = forw_raw_line(pos, &line);
+		if (linenum != 0)
+			linenum++;
+
+		if (pos == NULL_POSITION)
+		{
+			/*
+			 * We hit EOF without a match.
+			 */
+			error("Tag not found", NULL_PARG);
+			return (NULL_POSITION);
+		}
+
+		/*
+		 * If we're using line numbers, we might as well
+		 * remember the information we have now (the position
+		 * and line number of the current line).
+		 */
+		if (linenums)
+			add_lnum(linenum, pos);
+
+		/*
+		 * Test the line to see if we have a match.
+		 * Use strncmp because the pattern may be
+		 * truncated (in the tags file) if it is too long.
+		 * If tagendline is set, make sure we match all
+		 * the way to end of line (no extra chars after the match).
+		 */
+		len = strlen(tagpattern);
+		if (strncmp(tagpattern, line, len) == 0 &&
+		    (!tagendline || line[len] == '\0' || line[len] == '\r'))
+			break;
+	}
+
+	free(tagpattern);
+	tagpattern = NULL;
+	return (linepos);
+}
+
+#endif