1 /*-
2 * Copyright (c) 2002 Tim J. Robbins.
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 *
26 * $FreeBSD: src/usr.bin/csplit/csplit.c,v 1.9 2004/03/22 11:15:03 tjr Exp $
27 */
28
29 /*
30 * csplit -- split files based on context
31 *
32 * This utility splits its input into numbered output files by line number
33 * or by a regular expression. Regular expression matches have an optional
34 * offset with them, allowing the split to occur a specified number of
35 * lines before or after the match.
36 *
37 * To handle negative offsets, we stop reading when the match occurs and
38 * store the offset that the file should have been split at, then use
39 * this output file as input until all the "overflowed" lines have been read.
40 * The file is then closed and truncated to the correct length.
41 *
42 * We assume that the output files can be seeked upon (ie. they cannot be
43 * symlinks to named pipes or character devices), but make no such
44 * assumption about the input.
45 */
46
47 #include <sys/types.h>
48
49 #include <ctype.h>
50 #include <err.h>
51 #include <errno.h>
52 #include <limits.h>
53 #include <locale.h>
54 #include <regex.h>
55 #include <signal.h>
56 #include <stdint.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61
62 static void cleanup(void);
63 static void do_lineno(const char *);
64 static void do_rexp(const char *);
65 static char *get_line(void);
66 static void handlesig(int) __dead2;
67 static FILE *newfile(void);
68 static void toomuch(FILE *, long);
69 static void usage(void) __dead2;
70
71 /*
72 * Command line options
73 */
74 static const char *prefix; /* File name prefix */
75 static long sufflen; /* Number of decimal digits for suffix */
76 static int sflag; /* Suppress output of file names */
77 static int kflag; /* Keep output if error occurs */
78
79 /*
80 * Other miscellaneous globals (XXX too many)
81 */
82 static long lineno; /* Current line number in input file */
83 static long reps; /* Number of repetitions for this pattern */
84 static long nfiles; /* Number of files output so far */
85 static long maxfiles; /* Maximum number of files we can create */
86 static char currfile[PATH_MAX]; /* Current output file */
87 static const char *infn; /* Name of the input file */
88 static FILE *infile; /* Input file handle */
89 static FILE *overfile; /* Overflow file for toomuch() */
90 static off_t truncofs; /* Offset this file should be truncated at */
91 static int doclean; /* Should cleanup() remove output? */
92
93 int
main(int argc,char * argv[])94 main(int argc, char *argv[])
95 {
96 struct sigaction sa;
97 long i;
98 int ch;
99 const char *expr;
100 char *ep, *p;
101 FILE *ofp;
102
103 setlocale(LC_ALL, "");
104
105 kflag = sflag = 0;
106 prefix = "xx";
107 sufflen = 2;
108 while ((ch = getopt(argc, argv, "ksf:n:")) > 0) {
109 switch (ch) {
110 case 'f':
111 prefix = optarg;
112 break;
113 case 'k':
114 kflag = 1;
115 break;
116 case 'n':
117 errno = 0;
118 sufflen = strtol(optarg, &ep, 10);
119 if (sufflen <= 0 || *ep != '\0' || errno != 0)
120 errx(1, "%s: bad suffix length", optarg);
121 break;
122 case 's':
123 sflag = 1;
124 break;
125 default:
126 usage();
127 /*NOTREACHED*/
128 }
129 }
130
131 if (sufflen + strlen(prefix) >= PATH_MAX)
132 errx(1, "name too long");
133
134 argc -= optind;
135 argv += optind;
136
137 if ((infn = *argv++) == NULL)
138 usage();
139 if (strcmp(infn, "-") == 0) {
140 infile = stdin;
141 infn = "stdin";
142 } else if ((infile = fopen(infn, "r")) == NULL)
143 err(1, "%s", infn);
144
145 if (!kflag) {
146 doclean = 1;
147 atexit(cleanup);
148 sa.sa_flags = 0;
149 sa.sa_handler = handlesig;
150 sigemptyset(&sa.sa_mask);
151 sigaddset(&sa.sa_mask, SIGHUP);
152 sigaddset(&sa.sa_mask, SIGINT);
153 sigaddset(&sa.sa_mask, SIGTERM);
154 sigaction(SIGHUP, &sa, NULL);
155 sigaction(SIGINT, &sa, NULL);
156 sigaction(SIGTERM, &sa, NULL);
157 }
158
159 lineno = 0;
160 nfiles = 0;
161 truncofs = 0;
162 overfile = NULL;
163
164 /* Ensure 10^sufflen < LONG_MAX. */
165 for (maxfiles = 1, i = 0; i < sufflen; i++) {
166 if (maxfiles > LONG_MAX / 10)
167 errx(1, "%ld: suffix too long (limit %ld)",
168 sufflen, i);
169 maxfiles *= 10;
170 }
171
172 /* Create files based on supplied patterns. */
173 while (nfiles < maxfiles - 1 && (expr = *argv++) != NULL) {
174 /* Look ahead & see if this pattern has any repetitions. */
175 if (*argv != NULL && **argv == '{') {
176 errno = 0;
177 reps = strtol(*argv + 1, &ep, 10);
178 if (reps < 0 || *ep != '}' || errno != 0)
179 errx(1, "%s: bad repetition count", *argv + 1);
180 argv++;
181 } else
182 reps = 0;
183
184 if (*expr == '/' || *expr == '%') {
185 do
186 do_rexp(expr);
187 while (reps-- != 0 && nfiles < maxfiles - 1);
188 } else if (isdigit((unsigned char)*expr))
189 do_lineno(expr);
190 else
191 errx(1, "%s: unrecognised pattern", expr);
192 }
193
194 /* Copy the rest into a new file. */
195 if (!feof(infile)) {
196 ofp = newfile();
197 while ((p = get_line()) != NULL && fputs(p, ofp) == 0)
198 ;
199 if (!sflag)
200 printf("%jd\n", (intmax_t)ftello(ofp));
201 if (fclose(ofp) != 0)
202 err(1, "%s", currfile);
203 }
204
205 toomuch(NULL, 0);
206 doclean = 0;
207
208 return (0);
209 }
210
211 static void
usage(void)212 usage(void)
213 {
214
215 fprintf(stderr,
216 "usage: csplit [-ks] [-f prefix] [-n number] file args ...\n");
217 exit(1);
218 }
219
220 static void
handlesig(int sig __unused)221 handlesig(int sig __unused)
222 {
223 const char msg[] = "csplit: caught signal, cleaning up\n";
224
225 write(STDERR_FILENO, msg, sizeof(msg) - 1);
226 cleanup();
227 _exit(2);
228 }
229
230 /* Create a new output file. */
231 static FILE *
newfile(void)232 newfile(void)
233 {
234 FILE *fp;
235
236 if ((size_t)snprintf(currfile, sizeof(currfile), "%s%0*ld", prefix,
237 (int)sufflen, nfiles) >= sizeof(currfile))
238 errc(1, ENAMETOOLONG, NULL);
239 if ((fp = fopen(currfile, "w+")) == NULL)
240 err(1, "%s", currfile);
241 nfiles++;
242
243 return (fp);
244 }
245
246 /* Remove partial output, called before exiting. */
247 static void
cleanup(void)248 cleanup(void)
249 {
250 char fnbuf[PATH_MAX];
251 long i;
252
253 if (!doclean)
254 return;
255
256 /*
257 * NOTE: One cannot portably assume to be able to call snprintf()
258 * from inside a signal handler. It does, however, appear to be safe
259 * to do on FreeBSD. The solution to this problem is worse than the
260 * problem itself.
261 */
262
263 for (i = 0; i < nfiles; i++) {
264 snprintf(fnbuf, sizeof(fnbuf), "%s%0*ld", prefix,
265 (int)sufflen, i);
266 unlink(fnbuf);
267 }
268 }
269
270 /* Read a line from the input into a static buffer. */
271 static char *
get_line(void)272 get_line(void)
273 {
274 static char lbuf[LINE_MAX];
275 FILE *src;
276
277 src = overfile != NULL ? overfile : infile;
278
279 again: if (fgets(lbuf, sizeof(lbuf), src) == NULL) {
280 if (src == overfile) {
281 src = infile;
282 goto again;
283 }
284 return (NULL);
285 }
286 if (ferror(src))
287 err(1, "%s", infn);
288 lineno++;
289
290 return (lbuf);
291 }
292
293 /* Conceptually rewind the input (as obtained by get_line()) back `n' lines. */
294 static void
toomuch(FILE * ofp,long n)295 toomuch(FILE *ofp, long n)
296 {
297 char buf[BUFSIZ];
298 size_t i, nread;
299
300 if (overfile != NULL) {
301 /*
302 * Truncate the previous file we overflowed into back to
303 * the correct length, close it.
304 */
305 if (fflush(overfile) != 0)
306 err(1, "overflow");
307 if (ftruncate(fileno(overfile), truncofs) != 0)
308 err(1, "overflow");
309 if (fclose(overfile) != 0)
310 err(1, "overflow");
311 overfile = NULL;
312 }
313
314 if (n == 0)
315 /* Just tidying up */
316 return;
317
318 lineno -= n;
319
320 /*
321 * Wind the overflow file backwards to `n' lines before the
322 * current one.
323 */
324 do {
325 if (ftello(ofp) < (off_t)sizeof(buf))
326 rewind(ofp);
327 else
328 fseeko(ofp, -(off_t)sizeof(buf), SEEK_CUR);
329 if (ferror(ofp))
330 errx(1, "%s: can't seek", currfile);
331 if ((nread = fread(buf, 1, sizeof(buf), ofp)) == 0)
332 errx(1, "can't read overflowed output");
333 if (fseeko(ofp, -(off_t)nread, SEEK_CUR) != 0)
334 err(1, "%s", currfile);
335 for (i = 1; i <= nread; i++)
336 if (buf[nread - i] == '\n' && n-- == 0)
337 break;
338 if (ftello(ofp) == 0)
339 break;
340 } while (n > 0);
341 if (fseeko(ofp, nread - i + 1, SEEK_CUR) != 0)
342 err(1, "%s", currfile);
343
344 /*
345 * get_line() will read from here. Next call will truncate to
346 * truncofs in this file.
347 */
348 overfile = ofp;
349 truncofs = ftello(overfile);
350 }
351
352 /* Handle splits for /regexp/ and %regexp% patterns. */
353 static void
do_rexp(const char * expr)354 do_rexp(const char *expr)
355 {
356 regex_t cre;
357 intmax_t nwritten;
358 long ofs;
359 int first;
360 char *ecopy, *ep, *p, *pofs, *re;
361 FILE *ofp;
362
363 if ((ecopy = strdup(expr)) == NULL)
364 err(1, "strdup");
365
366 re = ecopy + 1;
367 if ((pofs = strrchr(ecopy, *expr)) == NULL || pofs[-1] == '\\')
368 errx(1, "%s: missing trailing %c", expr, *expr);
369 *pofs++ = '\0';
370
371 if (*pofs != '\0') {
372 errno = 0;
373 ofs = strtol(pofs, &ep, 10);
374 if (*ep != '\0' || errno != 0)
375 errx(1, "%s: bad offset", pofs);
376 } else
377 ofs = 0;
378
379 if (regcomp(&cre, re, REG_BASIC|REG_NOSUB) != 0)
380 errx(1, "%s: bad regular expression", re);
381
382 if (*expr == '/')
383 /* /regexp/: Save results to a file. */
384 ofp = newfile();
385 else {
386 /* %regexp%: Make a temporary file for overflow. */
387 if ((ofp = tmpfile()) == NULL)
388 err(1, "tmpfile");
389 }
390
391 /* Read and output lines until we get a match. */
392 first = 1;
393 while ((p = get_line()) != NULL) {
394 if (fputs(p, ofp) != 0)
395 break;
396 if (!first && regexec(&cre, p, 0, NULL, 0) == 0)
397 break;
398 first = 0;
399 }
400
401 if (p == NULL)
402 errx(1, "%s: no match", re);
403
404 if (ofs <= 0) {
405 /*
406 * Negative (or zero) offset: throw back any lines we should
407 * not have read yet.
408 */
409 if (p != NULL) {
410 toomuch(ofp, -ofs + 1);
411 nwritten = (intmax_t)truncofs;
412 } else
413 nwritten = (intmax_t)ftello(ofp);
414 } else {
415 /*
416 * Positive offset: copy the requested number of lines
417 * after the match.
418 */
419 while (--ofs > 0 && (p = get_line()) != NULL)
420 fputs(p, ofp);
421 toomuch(NULL, 0);
422 nwritten = (intmax_t)ftello(ofp);
423 if (fclose(ofp) != 0)
424 err(1, "%s", currfile);
425 }
426
427 if (!sflag && *expr == '/')
428 printf("%jd\n", nwritten);
429
430 regfree(&cre);
431 free(ecopy);
432 }
433
434 /* Handle splits based on line number. */
435 static void
do_lineno(const char * expr)436 do_lineno(const char *expr)
437 {
438 long lastline, tgtline;
439 char *ep, *p;
440 FILE *ofp;
441
442 errno = 0;
443 tgtline = strtol(expr, &ep, 10);
444 if (tgtline <= 0 || errno != 0 || *ep != '\0')
445 errx(1, "%s: bad line number", expr);
446 lastline = tgtline;
447 if (lastline <= lineno)
448 errx(1, "%s: can't go backwards", expr);
449
450 while (nfiles < maxfiles - 1) {
451 ofp = newfile();
452 while (lineno + 1 != lastline) {
453 if ((p = get_line()) == NULL)
454 errx(1, "%ld: out of range", lastline);
455 if (fputs(p, ofp) != 0)
456 break;
457 }
458 if (!sflag)
459 printf("%jd\n", (intmax_t)ftello(ofp));
460 if (fclose(ofp) != 0)
461 err(1, "%s", currfile);
462 if (reps-- == 0)
463 break;
464 lastline += tgtline;
465 }
466 }
467