1 /* $NetBSD: csplit.c,v 1.7 2017/07/30 23:02:53 cheusov Exp $ */
2 /* $FreeBSD: src/usr.bin/csplit/csplit.c,v 1.9 2004/03/22 11:15:03 tjr Exp$ */
3
4 /*-
5 * Copyright (c) 2002 Tim J. Robbins.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29
30 /*
31 * csplit -- split files based on context
32 *
33 * This utility splits its input into numbered output files by line number
34 * or by a regular expression. Regular expression matches have an optional
35 * offset with them, allowing the split to occur a specified number of
36 * lines before or after the match.
37 *
38 * To handle negative offsets, we stop reading when the match occurs and
39 * store the offset that the file should have been split at, then use
40 * this output file as input until all the "overflowed" lines have been read.
41 * The file is then closed and truncated to the correct length.
42 *
43 * We assume that the output files can be seeked upon (ie. they cannot be
44 * symlinks to named pipes or character devices), but make no such
45 * assumption about the input.
46 */
47
48 #include <sys/cdefs.h>
49 #ifndef lint
50 __RCSID("$NetBSD: csplit.c,v 1.7 2017/07/30 23:02:53 cheusov Exp $");
51 #endif
52
53 #include <sys/types.h>
54
55 #include <ctype.h>
56 #include <err.h>
57 #include <errno.h>
58 #include <limits.h>
59 #include <locale.h>
60 #include <regex.h>
61 #include <signal.h>
62 #include <stdint.h>
63 #include <stdio.h>
64 #include <stdlib.h>
65 #include <string.h>
66 #include <unistd.h>
67 #include <util.h>
68
69 static void cleanup(void);
70 static void do_lineno(const char *);
71 static void do_rexp(const char *);
72 static char *get_line(void);
73 static void handlesig(int);
74 static FILE *newfile(void);
75 static void toomuch(FILE *, long);
76 static void usage(void) __dead;
77
78 /*
79 * Command line options
80 */
81 static const char *prefix; /* File name prefix */
82 static long sufflen; /* Number of decimal digits for suffix */
83 static int sflag; /* Suppress output of file names */
84 static int kflag; /* Keep output if error occurs */
85
86 /*
87 * Other miscellaneous globals (XXX too many)
88 */
89 static long lineno; /* Current line number in input file */
90 static long reps; /* Number of repetitions for this pattern */
91 static long nfiles; /* Number of files output so far */
92 static long maxfiles; /* Maximum number of files we can create */
93 static char currfile[PATH_MAX]; /* Current output file */
94 static const char *infn; /* Name of the input file */
95 static FILE *infile; /* Input file handle */
96 static FILE *overfile; /* Overflow file for toomuch() */
97 static off_t truncofs; /* Offset this file should be truncated at */
98 static int doclean; /* Should cleanup() remove output? */
99
100 int
main(int argc,char * argv[])101 main(int argc, char *argv[])
102 {
103 struct sigaction sa;
104 long i;
105 int ch;
106 const char *expr;
107 char *ep, *p;
108 FILE *ofp;
109
110 (void)setlocale(LC_ALL, "");
111
112 kflag = sflag = 0;
113 prefix = "xx";
114 sufflen = 2;
115 while ((ch = getopt(argc, argv, "ksf:n:")) > 0) {
116 switch (ch) {
117 case 'f':
118 prefix = optarg;
119 break;
120 case 'k':
121 kflag = 1;
122 break;
123 case 'n':
124 errno = 0;
125 sufflen = strtol(optarg, &ep, 10);
126 if (sufflen <= 0 || *ep != '\0' || errno != 0)
127 errx(1, "%s: bad suffix length", optarg);
128 break;
129 case 's':
130 sflag = 1;
131 break;
132 default:
133 usage();
134 /*NOTREACHED*/
135 }
136 }
137
138 if (sufflen + strlen(prefix) >= PATH_MAX)
139 errx(1, "name too long");
140
141 argc -= optind;
142 argv += optind;
143
144 if ((infn = *argv++) == NULL)
145 usage();
146 if (strcmp(infn, "-") == 0) {
147 infile = stdin;
148 infn = "stdin";
149 } else if ((infile = fopen(infn, "r")) == NULL)
150 err(1, "%s", infn);
151
152 if (!kflag) {
153 doclean = 1;
154 (void)atexit(cleanup);
155 sa.sa_flags = 0;
156 sa.sa_handler = handlesig;
157 (void)sigemptyset(&sa.sa_mask);
158 (void)sigaddset(&sa.sa_mask, SIGHUP);
159 (void)sigaddset(&sa.sa_mask, SIGINT);
160 (void)sigaddset(&sa.sa_mask, SIGTERM);
161 (void)sigaction(SIGHUP, &sa, NULL);
162 (void)sigaction(SIGINT, &sa, NULL);
163 (void)sigaction(SIGTERM, &sa, NULL);
164 }
165
166 lineno = 0;
167 nfiles = 0;
168 truncofs = 0;
169 overfile = NULL;
170
171 /* Ensure 10^sufflen < LONG_MAX. */
172 for (maxfiles = 1, i = 0; i < sufflen; i++) {
173 if (maxfiles > LONG_MAX / 10)
174 errx(1, "%ld: suffix too long (limit %ld)",
175 sufflen, i);
176 maxfiles *= 10;
177 }
178
179 /* Create files based on supplied patterns. */
180 while (nfiles < maxfiles - 1 && (expr = *argv++) != NULL) {
181 /* Look ahead & see if this pattern has any repetitions. */
182 if (*argv != NULL && **argv == '{') {
183 errno = 0;
184 reps = strtol(*argv + 1, &ep, 10);
185 if (reps < 0 || *ep != '}' || errno != 0)
186 errx(1, "%s: bad repetition count", *argv + 1);
187 argv++;
188 } else
189 reps = 0;
190
191 if (*expr == '/' || *expr == '%') {
192 do
193 do_rexp(expr);
194 while (reps-- != 0 && nfiles < maxfiles - 1);
195 } else if (isdigit((unsigned char)*expr))
196 do_lineno(expr);
197 else
198 errx(1, "%s: unrecognised pattern", expr);
199 }
200
201 /* Copy the rest into a new file. */
202 if (!feof(infile)) {
203 ofp = newfile();
204 while ((p = get_line()) != NULL && fputs(p, ofp) != EOF)
205 ;
206 if (!sflag)
207 (void)printf("%jd\n", (intmax_t)ftello(ofp));
208 if (fclose(ofp) != 0)
209 err(1, "%s", currfile);
210 }
211
212 toomuch(NULL, 0L);
213 doclean = 0;
214
215 return (0);
216 }
217
218 static void
usage(void)219 usage(void)
220 {
221
222 (void)fprintf(stderr,
223 "Usage: %s [-ks] [-f prefix] [-n number] file args ...\n", getprogname());
224 exit(1);
225 }
226
227 __dead static void
handlesig(int sig)228 handlesig(int sig)
229 {
230 char msg[BUFSIZ];
231 size_t len;
232
233 len = snprintf(msg, sizeof(msg), "%s: Caught %s, cleaning up\n",
234 getprogname(), strsignal(sig));
235 if (len < sizeof(msg))
236 (void)write(STDERR_FILENO, msg, len);
237 cleanup();
238 (void)raise_default_signal(sig);
239 _exit(2);
240 }
241
242 /* Create a new output file. */
243 static FILE *
newfile(void)244 newfile(void)
245 {
246 FILE *fp;
247
248 if ((size_t)snprintf(currfile, sizeof(currfile), "%s%0*ld", prefix,
249 (int)sufflen, nfiles) >= sizeof(currfile))
250 errx(1, "%s: %s", currfile, strerror(ENAMETOOLONG));
251 if ((fp = fopen(currfile, "w+")) == NULL)
252 err(1, "%s", currfile);
253 nfiles++;
254
255 return (fp);
256 }
257
258 /* Remove partial output, called before exiting. */
259 static void
cleanup(void)260 cleanup(void)
261 {
262 char fnbuf[PATH_MAX];
263 long i;
264
265 if (!doclean)
266 return;
267
268 /*
269 * NOTE: One cannot portably assume to be able to call snprintf()
270 * from inside a signal handler. It does, however, appear to be safe
271 * to do on FreeBSD and NetBSD. The solution to this problem is worse
272 * than the problem itself.
273 */
274
275 for (i = 0; i < nfiles; i++) {
276 (void)snprintf(fnbuf, sizeof(fnbuf), "%s%0*ld", prefix,
277 (int)sufflen, i);
278 (void)unlink(fnbuf);
279 }
280 }
281
282 /* Read a line from the input into a static buffer. */
283 static char *
get_line(void)284 get_line(void)
285 {
286 static char lbuf[LINE_MAX];
287 FILE *src;
288
289 src = overfile != NULL ? overfile : infile;
290
291 again: if (fgets(lbuf, sizeof(lbuf), src) == NULL) {
292 if (src == overfile) {
293 src = infile;
294 goto again;
295 }
296 return (NULL);
297 }
298 if (ferror(src))
299 err(1, "%s", infn);
300 lineno++;
301
302 return (lbuf);
303 }
304
305 /* Conceptually rewind the input (as obtained by get_line()) back `n' lines. */
306 static void
toomuch(FILE * ofp,long n)307 toomuch(FILE *ofp, long n)
308 {
309 char buf[BUFSIZ];
310 size_t i, nread;
311
312 if (overfile != NULL) {
313 /*
314 * Truncate the previous file we overflowed into back to
315 * the correct length, close it.
316 */
317 if (fflush(overfile) != 0)
318 err(1, "overflow");
319 if (ftruncate(fileno(overfile), truncofs) != 0)
320 err(1, "overflow");
321 if (fclose(overfile) != 0)
322 err(1, "overflow");
323 overfile = NULL;
324 }
325
326 if (n == 0)
327 /* Just tidying up */
328 return;
329
330 lineno -= n;
331
332 /*
333 * Wind the overflow file backwards to `n' lines before the
334 * current one.
335 */
336 do {
337 if (ftello(ofp) < (off_t)sizeof(buf))
338 rewind(ofp);
339 else
340 (void)fseeko(ofp, -(off_t)sizeof(buf), SEEK_CUR);
341 if (ferror(ofp))
342 errx(1, "%s: can't seek", currfile);
343 if ((nread = fread(buf, 1, sizeof(buf), ofp)) == 0)
344 errx(1, "can't read overflowed output");
345 if (fseeko(ofp, -(off_t)nread, SEEK_CUR) != 0)
346 err(1, "%s", currfile);
347 for (i = 1; i <= nread; i++)
348 if (buf[nread - i] == '\n' && n-- == 0)
349 break;
350 if (ftello(ofp) == 0)
351 break;
352 } while (n > 0);
353 if (fseeko(ofp, (off_t)nread - i + 1, SEEK_CUR) != 0)
354 err(1, "%s", currfile);
355
356 /*
357 * get_line() will read from here. Next call will truncate to
358 * truncofs in this file.
359 */
360 overfile = ofp;
361 truncofs = ftello(overfile);
362 }
363
364 /* Handle splits for /regexp/ and %regexp% patterns. */
365 static void
do_rexp(const char * expr)366 do_rexp(const char *expr)
367 {
368 regex_t cre;
369 intmax_t nwritten;
370 long ofs;
371 int first;
372 char *ecopy, *ep, *p, *pofs, *re;
373 FILE *ofp;
374
375 if ((ecopy = strdup(expr)) == NULL)
376 err(1, "strdup");
377
378 re = ecopy + 1;
379 if ((pofs = strrchr(ecopy, *expr)) == NULL || pofs[-1] == '\\')
380 errx(1, "%s: missing trailing %c", expr, *expr);
381 *pofs++ = '\0';
382
383 if (*pofs != '\0') {
384 errno = 0;
385 ofs = strtol(pofs, &ep, 10);
386 if (*ep != '\0' || errno != 0)
387 errx(1, "%s: bad offset", pofs);
388 } else
389 ofs = 0;
390
391 if (regcomp(&cre, re, REG_BASIC|REG_NOSUB) != 0)
392 errx(1, "%s: bad regular expression", re);
393
394 if (*expr == '/')
395 /* /regexp/: Save results to a file. */
396 ofp = newfile();
397 else {
398 /* %regexp%: Make a temporary file for overflow. */
399 if ((ofp = tmpfile()) == NULL)
400 err(1, "tmpfile");
401 }
402
403 /* Read and output lines until we get a match. */
404 first = 1;
405 while ((p = get_line()) != NULL) {
406 if (fputs(p, ofp) == EOF)
407 break;
408 if (!first && regexec(&cre, p, 0, NULL, 0) == 0)
409 break;
410 first = 0;
411 }
412
413 if (p == NULL)
414 errx(1, "%s: no match", re);
415
416 if (ofs <= 0) {
417 /*
418 * Negative (or zero) offset: throw back any lines we should
419 * not have read yet.
420 */
421 if (p != NULL) {
422 toomuch(ofp, -ofs + 1);
423 nwritten = (intmax_t)truncofs;
424 } else
425 nwritten = (intmax_t)ftello(ofp);
426 } else {
427 /*
428 * Positive offset: copy the requested number of lines
429 * after the match.
430 */
431 while (--ofs > 0 && (p = get_line()) != NULL)
432 if (fputs(p, ofp) == EOF)
433 break;
434 toomuch(NULL, 0L);
435 nwritten = (intmax_t)ftello(ofp);
436 if (fclose(ofp) != 0)
437 err(1, "%s", currfile);
438 }
439
440 if (!sflag && *expr == '/')
441 (void)printf("%jd\n", nwritten);
442
443 regfree(&cre);
444 free(ecopy);
445 }
446
447 /* Handle splits based on line number. */
448 static void
do_lineno(const char * expr)449 do_lineno(const char *expr)
450 {
451 long lastline, tgtline;
452 char *ep, *p;
453 FILE *ofp;
454
455 errno = 0;
456 tgtline = strtol(expr, &ep, 10);
457 if (tgtline <= 0 || errno != 0 || *ep != '\0')
458 errx(1, "%s: bad line number", expr);
459 lastline = tgtline;
460 if (lastline <= lineno)
461 errx(1, "%s: can't go backwards", expr);
462
463 while (nfiles < maxfiles - 1) {
464 ofp = newfile();
465 while (lineno + 1 != lastline) {
466 if ((p = get_line()) == NULL)
467 errx(1, "%ld: out of range", lastline);
468 if (fputs(p, ofp) == EOF)
469 break;
470 }
471 if (!sflag)
472 (void)printf("%jd\n", (intmax_t)ftello(ofp));
473 if (fclose(ofp) != 0)
474 err(1, "%s", currfile);
475 if (reps-- == 0)
476 break;
477 lastline += tgtline;
478 }
479 }
480