| 1 | /* |
| 2 | * Copyright (c) 1988 Mark Nudleman |
| 3 | * Copyright (c) 1988 Regents of the University of California. |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms are permitted |
| 7 | * provided that the above copyright notice and this paragraph are |
| 8 | * duplicated in all such forms and that any documentation, |
| 9 | * advertising materials, and other materials related to such |
| 10 | * distribution and use acknowledge that the software was developed |
| 11 | * by Mark Nudleman and the University of California, Berkeley. The |
| 12 | * name of Mark Nudleman or the |
| 13 | * University may not be used to endorse or promote products derived |
| 14 | * from this software without specific prior written permission. |
| 15 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
| 16 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
| 17 | * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
| 18 | */ |
| 19 | |
| 20 | #ifndef lint |
| 21 | static char sccsid[] = "@(#)tags.c 5.4 (Berkeley) %G%"; |
| 22 | #endif /* not lint */ |
| 23 | |
| 24 | #include <sys/types.h> |
| 25 | #include <stdio.h> |
| 26 | #include <less.h> |
| 27 | |
| 28 | #define WHITESP(c) ((c)==' ' || (c)=='\t') |
| 29 | |
| 30 | char *tagfile; |
| 31 | char *tagpattern; |
| 32 | |
| 33 | static char *tags = "tags"; |
| 34 | |
| 35 | extern int linenums; |
| 36 | extern int sigs; |
| 37 | extern char *line; |
| 38 | |
| 39 | /* |
| 40 | * Find a tag in the "tags" file. |
| 41 | * Sets "tagfile" to the name of the file containing the tag, |
| 42 | * and "tagpattern" to the search pattern which should be used |
| 43 | * to find the tag. |
| 44 | */ |
| 45 | findtag(tag) |
| 46 | register char *tag; |
| 47 | { |
| 48 | register char *p; |
| 49 | register FILE *f; |
| 50 | register int taglen; |
| 51 | int search_char; |
| 52 | static char tline[200]; |
| 53 | |
| 54 | if ((f = fopen(tags, "r")) == NULL) |
| 55 | { |
| 56 | error("No tags file"); |
| 57 | tagfile = NULL; |
| 58 | return; |
| 59 | } |
| 60 | |
| 61 | taglen = strlen(tag); |
| 62 | |
| 63 | /* |
| 64 | * Search the tags file for the desired tag. |
| 65 | */ |
| 66 | while (fgets(tline, sizeof(tline), f) != NULL) |
| 67 | { |
| 68 | if (strncmp(tag, tline, taglen) != 0 || !WHITESP(tline[taglen])) |
| 69 | continue; |
| 70 | |
| 71 | /* |
| 72 | * Found it. |
| 73 | * The line contains the tag, the filename and the |
| 74 | * pattern, separated by white space. |
| 75 | * The pattern is surrounded by a pair of identical |
| 76 | * search characters. |
| 77 | * Parse the line and extract these parts. |
| 78 | */ |
| 79 | tagfile = tagpattern = NULL; |
| 80 | |
| 81 | /* |
| 82 | * Skip over the whitespace after the tag name. |
| 83 | */ |
| 84 | for (p = tline; !WHITESP(*p) && *p != '\0'; p++) |
| 85 | continue; |
| 86 | while (WHITESP(*p)) |
| 87 | p++; |
| 88 | if (*p == '\0') |
| 89 | /* File name is missing! */ |
| 90 | continue; |
| 91 | |
| 92 | /* |
| 93 | * Save the file name. |
| 94 | * Skip over the whitespace after the file name. |
| 95 | */ |
| 96 | tagfile = p; |
| 97 | while (!WHITESP(*p) && *p != '\0') |
| 98 | p++; |
| 99 | *p++ = '\0'; |
| 100 | while (WHITESP(*p)) |
| 101 | p++; |
| 102 | if (*p == '\0') |
| 103 | /* Pattern is missing! */ |
| 104 | continue; |
| 105 | |
| 106 | /* |
| 107 | * Save the pattern. |
| 108 | * Skip to the end of the pattern. |
| 109 | * Delete the initial "^" and the final "$" from the pattern. |
| 110 | */ |
| 111 | search_char = *p++; |
| 112 | if (*p == '^') |
| 113 | p++; |
| 114 | tagpattern = p; |
| 115 | while (*p != search_char && *p != '\0') |
| 116 | p++; |
| 117 | if (p[-1] == '$') |
| 118 | p--; |
| 119 | *p = '\0'; |
| 120 | |
| 121 | (void)fclose(f); |
| 122 | return; |
| 123 | } |
| 124 | (void)fclose(f); |
| 125 | error("No such tag in tags file"); |
| 126 | tagfile = NULL; |
| 127 | } |
| 128 | |
| 129 | /* |
| 130 | * Search for a tag. |
| 131 | * This is a stripped-down version of search(). |
| 132 | * We don't use search() for several reasons: |
| 133 | * - We don't want to blow away any search string we may have saved. |
| 134 | * - The various regular-expression functions (from different systems: |
| 135 | * regcmp vs. re_comp) behave differently in the presence of |
| 136 | * parentheses (which are almost always found in a tag). |
| 137 | */ |
| 138 | tagsearch() |
| 139 | { |
| 140 | off_t pos, linepos, forw_raw_line(); |
| 141 | int linenum; |
| 142 | |
| 143 | pos = (off_t)0; |
| 144 | linenum = find_linenum(pos); |
| 145 | |
| 146 | for (;;) |
| 147 | { |
| 148 | /* |
| 149 | * Get lines until we find a matching one or |
| 150 | * until we hit end-of-file. |
| 151 | */ |
| 152 | if (sigs) |
| 153 | return (1); |
| 154 | |
| 155 | /* |
| 156 | * Read the next line, and save the |
| 157 | * starting position of that line in linepos. |
| 158 | */ |
| 159 | linepos = pos; |
| 160 | pos = forw_raw_line(pos); |
| 161 | if (linenum != 0) |
| 162 | linenum++; |
| 163 | |
| 164 | if (pos == NULL_POSITION) |
| 165 | { |
| 166 | /* |
| 167 | * We hit EOF without a match. |
| 168 | */ |
| 169 | error("Tag not found"); |
| 170 | return (1); |
| 171 | } |
| 172 | |
| 173 | /* |
| 174 | * If we're using line numbers, we might as well |
| 175 | * remember the information we have now (the position |
| 176 | * and line number of the current line). |
| 177 | */ |
| 178 | if (linenums) |
| 179 | add_lnum(linenum, pos); |
| 180 | |
| 181 | /* |
| 182 | * Test the line to see if we have a match. |
| 183 | */ |
| 184 | if (strcmp(tagpattern, line) == 0) |
| 185 | break; |
| 186 | } |
| 187 | |
| 188 | jump_loc(linepos); |
| 189 | return (0); |
| 190 | } |