xref: /freebsd/usr.bin/locate/locate/locate.c (revision 4d846d26)
1 /*
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1995-2022 Wolfram Schneider <wosch@FreeBSD.org>
5  * Copyright (c) 1989, 1993
6  *      The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * James A. Woods.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 static const char copyright[] =
38 "@(#) Copyright (c) 1995-1996 Wolfram Schneider, Berlin.\n\
39 @(#) Copyright (c) 1989, 1993\n\
40         The Regents of the University of California.  All rights reserved.\n";
41 #endif /* not lint */
42 
43 #ifndef lint
44 #if 0
45 static char sccsid[] = "@(#)locate.c    8.1 (Berkeley) 6/6/93";
46 #endif
47 static const char rcsid[] =
48   "$FreeBSD$";
49 #endif /* not lint */
50 
51 /*
52  * Ref: Usenix ;login:, Vol 8, No 1, February/March, 1983, p. 8.
53  *
54  * Locate scans a file list for the full pathname of a file given only part
55  * of the name.  The list has been processed with with "front-compression"
56  * and bigram coding.  Front compression reduces space by a factor of 4-5,
57  * bigram coding by a further 20-25%.
58  *
59  * The codes are:
60  *
61  *      0-28    likeliest differential counts + offset to make nonnegative
62  *      30      switch code for out-of-range count to follow in next word
63  *      31      an 8 bit char followed
64  *      128-255 bigram codes (128 most common, as determined by 'updatedb')
65  *      32-127  single character (printable) ascii residue (ie, literal)
66  *
67  * A novel two-tiered string search technique is employed:
68  *
69  * First, a metacharacter-free subpattern and partial pathname is matched
70  * BACKWARDS to avoid full expansion of the pathname list.  The time savings
71  * is 40-50% over forward matching, which cannot efficiently handle
72  * overlapped search patterns and compressed path residue.
73  *
74  * Then, the actual shell glob-style regular expression (if in this form) is
75  * matched against the candidate pathnames using the slower routines provided
76  * in the standard 'find'.
77  */
78 
79 #include <sys/param.h>
80 #include <ctype.h>
81 #include <err.h>
82 #include <fnmatch.h>
83 #include <locale.h>
84 #include <stdio.h>
85 #include <stdlib.h>
86 #include <string.h>
87 #include <unistd.h>
88 
89 #ifdef MMAP
90 #  include <sys/types.h>
91 #  include <sys/stat.h>
92 #  include <sys/mman.h>
93 #  include <fcntl.h>
94 #endif
95 
96 #include "locate.h"
97 #include "pathnames.h"
98 
99 
100 int f_mmap;             /* use mmap */
101 int f_icase;            /* ignore case */
102 int f_stdin;            /* read database from stdin */
103 int f_statistic;        /* print statistic */
104 int f_silent;           /* suppress output, show only count of matches */
105 long f_limit;           /* limit number of output lines, 0 == infinite */
106 long counter;           /* counter for matches [-c] */
107 char separator='\n';	/* line separator */
108 
109 u_char myctype[UCHAR_MAX + 1];
110 
111 void    usage(void);
112 void    statistic(FILE *, char *);
113 void    fastfind(FILE *, char *, char *);
114 void    fastfind_icase(FILE *, char *, char *);
115 void    fastfind_mmap(char *, caddr_t, off_t, char *);
116 void    fastfind_mmap_icase(char *, caddr_t, off_t, char *);
117 void	search_mmap(char *, char **);
118 void	search_fopen(char *, char **);
119 unsigned long cputime(void);
120 
121 extern char     **colon(char **, char*, char*);
122 extern int      getwm(caddr_t);
123 extern int      getwf(FILE *);
124 extern u_char   *tolower_word(u_char *);
125 extern int	check_bigram_char(int);
126 extern char 	*patprep(char *);
127 extern void 	rebuild_message(char *db);
128 extern int 	check_size(char *db);
129 
130 int
131 main(int argc, char **argv)
132 {
133         int ch;
134         char **dbv = NULL;
135 	char *path_fcodes;      /* locate database */
136 #ifdef MMAP
137         f_mmap = 1;		/* mmap is default */
138 #endif
139 	(void) setlocale(LC_ALL, "");
140 
141         while ((ch = getopt(argc, argv, "0Scd:il:ms")) != -1)
142                 switch(ch) {
143                 case '0':	/* 'find -print0' style */
144 			separator = '\0';
145 			break;
146                 case 'S':	/* statistic lines */
147                         f_statistic = 1;
148                         break;
149                 case 'l': /* limit number of output lines, 0 == infinite */
150                         f_limit = atol(optarg);
151 			if (f_limit < 0 )
152 				errx(1, "invalid argument for -l: '%s'", optarg);
153                         break;
154                 case 'd':	/* database */
155                         dbv = colon(dbv, optarg, _PATH_FCODES);
156                         break;
157                 case 'i':	/* ignore case */
158                         f_icase = 1;
159                         break;
160                 case 'm':	/* mmap */
161 #ifdef MMAP
162                         f_mmap = 1;
163 #else
164 						warnx("mmap(2) not implemented");
165 #endif
166                         break;
167                 case 's':	/* stdio lib */
168                         f_mmap = 0;
169                         break;
170                 case 'c': /* suppress output, show only count of matches */
171                         f_silent = 1;
172                         break;
173                 default:
174                         usage();
175                 }
176         argv += optind;
177         argc -= optind;
178 
179         /* to few arguments */
180         if (argc < 1 && !(f_statistic))
181                 usage();
182 
183         /* no (valid) database as argument */
184         if (dbv == NULL || *dbv == NULL) {
185                 /* try to read database from environment */
186                 if ((path_fcodes = getenv("LOCATE_PATH")) == NULL ||
187 		     *path_fcodes == '\0')
188                         /* use default database */
189                         dbv = colon(dbv, _PATH_FCODES, _PATH_FCODES);
190                 else		/* $LOCATE_PATH */
191                         dbv = colon(dbv, path_fcodes, _PATH_FCODES);
192         }
193 
194         if (f_icase && UCHAR_MAX < 4096) /* init tolower lookup table */
195                 for (ch = 0; ch < UCHAR_MAX + 1; ch++)
196                         myctype[ch] = tolower(ch);
197 
198         /* foreach database ... */
199         while((path_fcodes = *dbv) != NULL) {
200                 dbv++;
201 
202                 if (!strcmp(path_fcodes, "-"))
203                         f_stdin = 1;
204 		else
205 			f_stdin = 0;
206 
207 #ifndef MMAP
208 		f_mmap = 0;	/* be paranoid */
209 #endif
210                 if (!f_mmap || f_stdin || f_statistic)
211 			search_fopen(path_fcodes, argv);
212                 else
213 			search_mmap(path_fcodes, argv);
214         }
215 
216         if (f_silent)
217 		printf("%ld\n", counter);
218         exit(0);
219 }
220 
221 /*
222  * Arguments:
223  * db	database
224  * s	search strings
225  */
226 void
227 search_fopen(char *db, char **s)
228 {
229 	FILE *fp;
230 
231 	/* can only read stdin once */
232 	if (f_stdin) {
233 		fp = stdin;
234 		if (*(s+1) != NULL) {
235 			warnx("read database from stdin, use only `%s' as pattern", *s);
236 			*(s+1) = NULL;
237 		}
238 	}
239 	else {
240 		if (!check_size(db))
241 			exit(1);
242 
243 		if ((fp = fopen(db, "r")) == NULL) {
244 			warn("`%s'", db);
245 			rebuild_message(db);
246 			exit(1);
247 		}
248 	}
249 
250 	/* count only chars or lines */
251 	if (f_statistic) {
252 		statistic(fp, db);
253 		(void)fclose(fp);
254 		return;
255 	}
256 
257 	/* foreach search string ... */
258 	while(*s != NULL) {
259 		if (!f_stdin &&
260 		    fseek(fp, (long)0, SEEK_SET) == -1)
261 			err(1, "fseek to begin of ``%s''\n", db);
262 
263 		if (f_icase)
264 			fastfind_icase(fp, *s, db);
265 		else
266 			fastfind(fp, *s, db);
267 		s++;
268 	}
269 	(void)fclose(fp);
270 }
271 
272 #ifdef MMAP
273 /*
274  * Arguments:
275  * db	database
276  * s	search strings
277  */
278 void
279 search_mmap(char *db, char **s)
280 {
281         struct stat sb;
282         int fd;
283         caddr_t p;
284         off_t len;
285 
286 	if (!check_size(db))
287 		exit(1);
288 
289 	if (stat(db, &sb) == -1)
290 		err(1, "stat");
291 
292 	len = sb.st_size;
293 
294 	if ((fd = open(db, O_RDONLY)) == -1) {
295 		warn("%s", db);
296 		rebuild_message(db);
297 		exit(1);
298         }
299 
300 	if ((p = mmap((caddr_t)0, (size_t)len,
301 		      PROT_READ, MAP_SHARED,
302 		      fd, (off_t)0)) == MAP_FAILED)
303 		err(1, "mmap ``%s''", db);
304 
305 	/* foreach search string ... */
306 	while (*s != NULL) {
307 		if (f_icase)
308 			fastfind_mmap_icase(*s, p, len, db);
309 		else
310 			fastfind_mmap(*s, p, len, db);
311 		s++;
312 	}
313 
314 	if (munmap(p, (size_t)len) == -1)
315 		warn("munmap %s\n", db);
316 
317 	(void)close(fd);
318 }
319 #endif /* MMAP */
320 
321 void
322 usage ()
323 {
324         (void)fprintf(stderr,
325 	"usage: locate [-0Scims] [-l limit] [-d database] pattern ...\n\n");
326         (void)fprintf(stderr,
327 	"default database: `%s' or $LOCATE_PATH\n", _PATH_FCODES);
328         exit(1);
329 }
330 
331 
332 /* load fastfind functions */
333 
334 /* statistic */
335 /* fastfind_mmap, fastfind_mmap_icase */
336 #ifdef MMAP
337 #undef FF_MMAP
338 #undef FF_ICASE
339 
340 #define FF_MMAP
341 #include "fastfind.c"
342 #define FF_ICASE
343 #include "fastfind.c"
344 #endif /* MMAP */
345 
346 /* fopen */
347 /* fastfind, fastfind_icase */
348 #undef FF_MMAP
349 #undef FF_ICASE
350 #include "fastfind.c"
351 #define FF_ICASE
352 #include "fastfind.c"
353