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