xref: /freebsd/usr.bin/locate/locate/locate.c (revision 4b9d6057)
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 /*
37  * Ref: Usenix ;login:, Vol 8, No 1, February/March, 1983, p. 8.
38  *
39  * Locate scans a file list for the full pathname of a file given only part
40  * of the name.  The list has been processed with with "front-compression"
41  * and bigram coding.  Front compression reduces space by a factor of 4-5,
42  * bigram coding by a further 20-25%.
43  *
44  * The codes are:
45  *
46  *      0-28    likeliest differential counts + offset to make nonnegative
47  *      30      switch code for out-of-range count to follow in next word
48  *      31      an 8 bit char followed
49  *      128-255 bigram codes (128 most common, as determined by 'updatedb')
50  *      32-127  single character (printable) ascii residue (ie, literal)
51  *
52  * A novel two-tiered string search technique is employed:
53  *
54  * First, a metacharacter-free subpattern and partial pathname is matched
55  * BACKWARDS to avoid full expansion of the pathname list.  The time savings
56  * is 40-50% over forward matching, which cannot efficiently handle
57  * overlapped search patterns and compressed path residue.
58  *
59  * Then, the actual shell glob-style regular expression (if in this form) is
60  * matched against the candidate pathnames using the slower routines provided
61  * in the standard 'find'.
62  */
63 
64 #include <sys/param.h>
65 #include <ctype.h>
66 #include <err.h>
67 #include <fnmatch.h>
68 #include <locale.h>
69 #include <stdio.h>
70 #include <stdlib.h>
71 #include <string.h>
72 #include <unistd.h>
73 
74 #ifdef MMAP
75 #  include <sys/types.h>
76 #  include <sys/stat.h>
77 #  include <sys/mman.h>
78 #  include <fcntl.h>
79 #endif
80 
81 #include "locate.h"
82 #include "pathnames.h"
83 
84 
85 int f_mmap;             /* use mmap */
86 int f_icase;            /* ignore case */
87 int f_stdin;            /* read database from stdin */
88 int f_statistic;        /* print statistic */
89 int f_silent;           /* suppress output, show only count of matches */
90 long f_limit;           /* limit number of output lines, 0 == infinite */
91 long counter;           /* counter for matches [-c] */
92 char separator='\n';	/* line separator */
93 
94 u_char myctype[UCHAR_MAX + 1];
95 
96 void    usage(void);
97 void    statistic(FILE *, char *);
98 void    fastfind(FILE *, char *, char *);
99 void    fastfind_icase(FILE *, char *, char *);
100 void    fastfind_mmap(char *, caddr_t, off_t, char *);
101 void    fastfind_mmap_icase(char *, caddr_t, off_t, char *);
102 void	search_mmap(char *, char **);
103 void	search_fopen(char *, char **);
104 unsigned long cputime(void);
105 
106 extern char     **colon(char **, char*, char*);
107 extern int      getwm(caddr_t);
108 extern int      getwf(FILE *);
109 extern u_char   *tolower_word(u_char *);
110 extern int	check_bigram_char(int);
111 extern char 	*patprep(char *);
112 extern void 	rebuild_message(char *db);
113 extern int 	check_size(char *db);
114 
115 int
116 main(int argc, char **argv)
117 {
118         int ch;
119         char **dbv = NULL;
120 	char *path_fcodes;      /* locate database */
121 #ifdef MMAP
122         f_mmap = 1;		/* mmap is default */
123 #endif
124 	(void) setlocale(LC_ALL, "");
125 
126         while ((ch = getopt(argc, argv, "0Scd:il:ms")) != -1)
127                 switch(ch) {
128                 case '0':	/* 'find -print0' style */
129 			separator = '\0';
130 			break;
131                 case 'S':	/* statistic lines */
132                         f_statistic = 1;
133                         break;
134                 case 'l': /* limit number of output lines, 0 == infinite */
135                         f_limit = atol(optarg);
136 			if (f_limit < 0 )
137 				errx(1, "invalid argument for -l: '%s'", optarg);
138                         break;
139                 case 'd':	/* database */
140                         dbv = colon(dbv, optarg, _PATH_FCODES);
141                         break;
142                 case 'i':	/* ignore case */
143                         f_icase = 1;
144                         break;
145                 case 'm':	/* mmap */
146 #ifdef MMAP
147                         f_mmap = 1;
148 #else
149 						warnx("mmap(2) not implemented");
150 #endif
151                         break;
152                 case 's':	/* stdio lib */
153                         f_mmap = 0;
154                         break;
155                 case 'c': /* suppress output, show only count of matches */
156                         f_silent = 1;
157                         break;
158                 default:
159                         usage();
160                 }
161         argv += optind;
162         argc -= optind;
163 
164         /* to few arguments */
165         if (argc < 1 && !(f_statistic))
166                 usage();
167 
168         /* no (valid) database as argument */
169         if (dbv == NULL || *dbv == NULL) {
170                 /* try to read database from environment */
171                 if ((path_fcodes = getenv("LOCATE_PATH")) == NULL ||
172 		     *path_fcodes == '\0')
173                         /* use default database */
174                         dbv = colon(dbv, _PATH_FCODES, _PATH_FCODES);
175                 else		/* $LOCATE_PATH */
176                         dbv = colon(dbv, path_fcodes, _PATH_FCODES);
177         }
178 
179         if (f_icase && UCHAR_MAX < 4096) /* init tolower lookup table */
180                 for (ch = 0; ch < UCHAR_MAX + 1; ch++)
181                         myctype[ch] = tolower(ch);
182 
183         /* foreach database ... */
184         while((path_fcodes = *dbv) != NULL) {
185                 dbv++;
186 
187                 if (!strcmp(path_fcodes, "-"))
188                         f_stdin = 1;
189 		else
190 			f_stdin = 0;
191 
192 #ifndef MMAP
193 		f_mmap = 0;	/* be paranoid */
194 #endif
195                 if (!f_mmap || f_stdin || f_statistic)
196 			search_fopen(path_fcodes, argv);
197                 else
198 			search_mmap(path_fcodes, argv);
199         }
200 
201         if (f_silent)
202 		printf("%ld\n", counter);
203         exit(0);
204 }
205 
206 /*
207  * Arguments:
208  * db	database
209  * s	search strings
210  */
211 void
212 search_fopen(char *db, char **s)
213 {
214 	FILE *fp;
215 
216 	/* can only read stdin once */
217 	if (f_stdin) {
218 		fp = stdin;
219 		if (*(s+1) != NULL) {
220 			warnx("read database from stdin, use only `%s' as pattern", *s);
221 			*(s+1) = NULL;
222 		}
223 	}
224 	else {
225 		if (!check_size(db))
226 			exit(1);
227 
228 		if ((fp = fopen(db, "r")) == NULL) {
229 			warn("`%s'", db);
230 			rebuild_message(db);
231 			exit(1);
232 		}
233 	}
234 
235 	/* count only chars or lines */
236 	if (f_statistic) {
237 		statistic(fp, db);
238 		(void)fclose(fp);
239 		return;
240 	}
241 
242 	/* foreach search string ... */
243 	while(*s != NULL) {
244 		if (!f_stdin &&
245 		    fseek(fp, (long)0, SEEK_SET) == -1)
246 			err(1, "fseek to begin of ``%s''\n", db);
247 
248 		if (f_icase)
249 			fastfind_icase(fp, *s, db);
250 		else
251 			fastfind(fp, *s, db);
252 		s++;
253 	}
254 	(void)fclose(fp);
255 }
256 
257 #ifdef MMAP
258 /*
259  * Arguments:
260  * db	database
261  * s	search strings
262  */
263 void
264 search_mmap(char *db, char **s)
265 {
266         struct stat sb;
267         int fd;
268         caddr_t p;
269         off_t len;
270 
271 	if (!check_size(db))
272 		exit(1);
273 
274 	if (stat(db, &sb) == -1)
275 		err(1, "stat");
276 
277 	len = sb.st_size;
278 
279 	if ((fd = open(db, O_RDONLY)) == -1) {
280 		warn("%s", db);
281 		rebuild_message(db);
282 		exit(1);
283         }
284 
285 	if ((p = mmap((caddr_t)0, (size_t)len,
286 		      PROT_READ, MAP_SHARED,
287 		      fd, (off_t)0)) == MAP_FAILED)
288 		err(1, "mmap ``%s''", db);
289 
290 	/* foreach search string ... */
291 	while (*s != NULL) {
292 		if (f_icase)
293 			fastfind_mmap_icase(*s, p, len, db);
294 		else
295 			fastfind_mmap(*s, p, len, db);
296 		s++;
297 	}
298 
299 	if (munmap(p, (size_t)len) == -1)
300 		warn("munmap %s\n", db);
301 
302 	(void)close(fd);
303 }
304 #endif /* MMAP */
305 
306 void
307 usage ()
308 {
309         (void)fprintf(stderr,
310 	"usage: locate [-0Scims] [-l limit] [-d database] pattern ...\n\n");
311         (void)fprintf(stderr,
312 	"default database: `%s' or $LOCATE_PATH\n", _PATH_FCODES);
313         exit(1);
314 }
315 
316 
317 /* load fastfind functions */
318 
319 /* statistic */
320 /* fastfind_mmap, fastfind_mmap_icase */
321 #ifdef MMAP
322 #undef FF_MMAP
323 #undef FF_ICASE
324 
325 #define FF_MMAP
326 #include "fastfind.c"
327 #define FF_ICASE
328 #include "fastfind.c"
329 #endif /* MMAP */
330 
331 /* fopen */
332 /* fastfind, fastfind_icase */
333 #undef FF_MMAP
334 #undef FF_ICASE
335 #include "fastfind.c"
336 #define FF_ICASE
337 #include "fastfind.c"
338