xref: /freebsd/usr.bin/split/split.c (revision d0b2dbfa)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1987, 1993, 1994
5  *	The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  */
31 
32 #include <sys/cdefs.h>
33 #ifndef lint
34 static const char copyright[] =
35 "@(#) Copyright (c) 1987, 1993, 1994\n\
36 	The Regents of the University of California.  All rights reserved.\n";
37 #endif
38 
39 #ifndef lint
40 static const char sccsid[] = "@(#)split.c	8.2 (Berkeley) 4/16/94";
41 #endif
42 
43 #include <sys/param.h>
44 #include <sys/types.h>
45 #include <sys/stat.h>
46 
47 #include <ctype.h>
48 #include <err.h>
49 #include <errno.h>
50 #include <fcntl.h>
51 #include <inttypes.h>
52 #include <libutil.h>
53 #include <limits.h>
54 #include <locale.h>
55 #include <stdbool.h>
56 #include <stdint.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <unistd.h>
61 #include <regex.h>
62 #include <sysexits.h>
63 
64 #define DEFLINE	1000			/* Default num lines per file. */
65 
66 static off_t	 bytecnt;		/* Byte count to split on. */
67 static off_t	 chunks = 0;		/* Chunks count to split into. */
68 static bool      clobber = true;        /* Whether to overwrite existing output files. */
69 static long	 numlines;		/* Line count to split on. */
70 static int	 file_open;		/* If a file open. */
71 static int	 ifd = -1, ofd = -1;	/* Input/output file descriptors. */
72 static char	 fname[MAXPATHLEN];	/* File name prefix. */
73 static regex_t	 rgx;
74 static int	 pflag;
75 static bool	 dflag;
76 static long	 sufflen = 2;		/* File name suffix length. */
77 static int	 autosfx = 1;		/* Whether to auto-extend the suffix length. */
78 
79 static void newfile(void);
80 static void split1(void);
81 static void split2(void);
82 static void split3(void);
83 static void usage(void) __dead2;
84 
85 int
86 main(int argc, char **argv)
87 {
88 	int ch;
89 	int error;
90 	char *ep, *p;
91 
92 	setlocale(LC_ALL, "");
93 
94 	dflag = false;
95 	while ((ch = getopt(argc, argv, "0123456789a:b:cdl:n:p:")) != -1)
96 		switch (ch) {
97 		case '0': case '1': case '2': case '3': case '4':
98 		case '5': case '6': case '7': case '8': case '9':
99 			/*
100 			 * Undocumented kludge: split was originally designed
101 			 * to take a number after a dash.
102 			 */
103 			if (numlines == 0) {
104 				p = argv[optind - 1];
105 				if (p[0] == '-' && p[1] == ch && !p[2])
106 					numlines = strtol(++p, &ep, 10);
107 				else
108 					numlines =
109 					    strtol(argv[optind] + 1, &ep, 10);
110 				if (numlines <= 0 || *ep)
111 					errx(EX_USAGE,
112 					    "%s: illegal line count", optarg);
113 			}
114 			break;
115 		case 'a':		/* Suffix length */
116 			if ((sufflen = strtol(optarg, &ep, 10)) <= 0 || *ep)
117 				errx(EX_USAGE,
118 				    "%s: illegal suffix length", optarg);
119 			autosfx = 0;
120 			break;
121 		case 'b':		/* Byte count. */
122 			errno = 0;
123 			error = expand_number(optarg, &bytecnt);
124 			if (error == -1)
125 				errx(EX_USAGE, "%s: offset too large", optarg);
126 			break;
127 		case 'c':               /* Continue, don't overwrite output files. */
128 			clobber = false;
129 			break;
130 		case 'd':		/* Decimal suffix */
131 			dflag = true;
132 			break;
133 		case 'l':		/* Line count. */
134 			if (numlines != 0)
135 				usage();
136 			if ((numlines = strtol(optarg, &ep, 10)) <= 0 || *ep)
137 				errx(EX_USAGE,
138 				    "%s: illegal line count", optarg);
139 			break;
140 		case 'n':		/* Chunks. */
141 			if (!isdigit((unsigned char)optarg[0]) ||
142 			    (chunks = (size_t)strtoul(optarg, &ep, 10)) == 0 ||
143 			    *ep != '\0') {
144 				errx(EX_USAGE, "%s: illegal number of chunks",
145 				     optarg);
146 			}
147 			break;
148 
149 		case 'p':		/* pattern matching. */
150 			if (regcomp(&rgx, optarg, REG_EXTENDED|REG_NOSUB) != 0)
151 				errx(EX_USAGE, "%s: illegal regexp", optarg);
152 			pflag = 1;
153 			break;
154 		default:
155 			usage();
156 		}
157 	argv += optind;
158 	argc -= optind;
159 
160 	if (*argv != NULL) {			/* Input file. */
161 		if (strcmp(*argv, "-") == 0)
162 			ifd = STDIN_FILENO;
163 		else if ((ifd = open(*argv, O_RDONLY, 0)) < 0)
164 			err(EX_NOINPUT, "%s", *argv);
165 		++argv;
166 	}
167 	if (*argv != NULL)			/* File name prefix. */
168 		if (strlcpy(fname, *argv++, sizeof(fname)) >= sizeof(fname))
169 			errx(EX_USAGE, "file name prefix is too long");
170 	if (*argv != NULL)
171 		usage();
172 
173 	if (strlen(fname) + (unsigned long)sufflen >= sizeof(fname))
174 		errx(EX_USAGE, "suffix is too long");
175 	if (pflag && (numlines != 0 || bytecnt != 0 || chunks != 0))
176 		usage();
177 
178 	if (numlines == 0)
179 		numlines = DEFLINE;
180 	else if (bytecnt != 0 || chunks != 0)
181 		usage();
182 
183 	if (bytecnt && chunks)
184 		usage();
185 
186 	if (ifd == -1)				/* Stdin by default. */
187 		ifd = 0;
188 
189 	if (bytecnt) {
190 		split1();
191 		exit (0);
192 	} else if (chunks) {
193 		split3();
194 		exit (0);
195 	}
196 	split2();
197 	if (pflag)
198 		regfree(&rgx);
199 	exit(0);
200 }
201 
202 /*
203  * split1 --
204  *	Split the input by bytes.
205  */
206 static void
207 split1(void)
208 {
209 	static char bfr[MAXBSIZE];
210 	off_t bcnt;
211 	char *C;
212 	ssize_t dist, len;
213 	int nfiles;
214 
215 	nfiles = 0;
216 
217 	for (bcnt = 0;;)
218 		switch ((len = read(ifd, bfr, sizeof(bfr)))) {
219 		case 0:
220 			exit(0);
221 		case -1:
222 			err(EX_IOERR, "read");
223 			/* NOTREACHED */
224 		default:
225 			if (!file_open) {
226 				if (!chunks || (nfiles < chunks)) {
227 					newfile();
228 					nfiles++;
229 				}
230 			}
231 			if (bcnt + len >= bytecnt) {
232 				dist = bytecnt - bcnt;
233 				if (write(ofd, bfr, dist) != dist)
234 					err(EX_IOERR, "write");
235 				len -= dist;
236 				for (C = bfr + dist; len >= bytecnt;
237 				    len -= bytecnt, C += bytecnt) {
238 					if (!chunks || (nfiles < chunks)) {
239 					newfile();
240 						nfiles++;
241 					}
242 					if (write(ofd,
243 					    C, bytecnt) != bytecnt)
244 						err(EX_IOERR, "write");
245 				}
246 				if (len != 0) {
247 					if (!chunks || (nfiles < chunks)) {
248 					newfile();
249 						nfiles++;
250 					}
251 					if (write(ofd, C, len) != len)
252 						err(EX_IOERR, "write");
253 				} else
254 					file_open = 0;
255 				bcnt = len;
256 			} else {
257 				bcnt += len;
258 				if (write(ofd, bfr, len) != len)
259 					err(EX_IOERR, "write");
260 			}
261 		}
262 }
263 
264 /*
265  * split2 --
266  *	Split the input by lines.
267  */
268 static void
269 split2(void)
270 {
271 	char *buf;
272 	size_t bufsize;
273 	ssize_t len;
274 	long lcnt = 0;
275 	FILE *infp;
276 
277 	buf = NULL;
278 	bufsize = 0;
279 
280 	/* Stick a stream on top of input file descriptor */
281 	if ((infp = fdopen(ifd, "r")) == NULL)
282 		err(EX_NOINPUT, "fdopen");
283 
284 	/* Process input one line at a time */
285 	while ((errno = 0, len = getline(&buf, &bufsize, infp)) > 0) {
286 		/* Check if we need to start a new file */
287 		if (pflag) {
288 			regmatch_t pmatch;
289 
290 			pmatch.rm_so = 0;
291 			pmatch.rm_eo = len - 1;
292 			if (regexec(&rgx, buf, 0, &pmatch, REG_STARTEND) == 0)
293 				newfile();
294 		} else if (lcnt++ == numlines) {
295 			newfile();
296 			lcnt = 1;
297 		}
298 
299 		/* Open output file if needed */
300 		if (!file_open)
301 			newfile();
302 
303 		/* Write out line */
304 		if (write(ofd, buf, len) != len)
305 			err(EX_IOERR, "write");
306 	}
307 
308 	/* EOF or error? */
309 	if ((len == -1 && errno != 0) || ferror(infp))
310 		err(EX_IOERR, "read");
311 	else
312 		exit(0);
313 }
314 
315 /*
316  * split3 --
317  *	Split the input into specified number of chunks
318  */
319 static void
320 split3(void)
321 {
322 	struct stat sb;
323 
324 	if (fstat(ifd, &sb) == -1) {
325 		err(1, "stat");
326 		/* NOTREACHED */
327 	}
328 
329 	if (chunks > sb.st_size) {
330 		errx(1, "can't split into more than %d files",
331 		    (int)sb.st_size);
332 		/* NOTREACHED */
333 	}
334 
335 	bytecnt = sb.st_size / chunks;
336 	split1();
337 }
338 
339 
340 /*
341  * newfile --
342  *	Open a new output file.
343  */
344 static void
345 newfile(void)
346 {
347 	long i, maxfiles, tfnum;
348 	static long fnum;
349 	static char *fpnt;
350 	char beg, end;
351 	int pattlen;
352 	int flags = O_WRONLY | O_CREAT | O_TRUNC;
353 
354 	if (!clobber)
355 		flags |= O_EXCL;
356 
357 	if (ofd == -1) {
358 		if (fname[0] == '\0') {
359 			fname[0] = 'x';
360 			fpnt = fname + 1;
361 		} else {
362 			fpnt = fname + strlen(fname);
363 		}
364 	} else if (close(ofd) != 0)
365 		err(1, "%s", fname);
366 
367 	again:
368 	if (dflag) {
369 		beg = '0';
370 		end = '9';
371 	}
372 	else {
373 		beg = 'a';
374 		end = 'z';
375 	}
376 	pattlen = end - beg + 1;
377 
378 	/*
379 	 * If '-a' is not specified, then we automatically expand the
380 	 * suffix length to accomodate splitting all input.  We do this
381 	 * by moving the suffix pointer (fpnt) forward and incrementing
382 	 * sufflen by one, thereby yielding an additional two characters
383 	 * and allowing all output files to sort such that 'cat *' yields
384 	 * the input in order.  I.e., the order is '... xyy xyz xzaaa
385 	 * xzaab ... xzyzy, xzyzz, xzzaaaa, xzzaaab' and so on.
386 	 */
387 	if (!dflag && autosfx && (fpnt[0] == 'y') &&
388 			strspn(fpnt+1, "z") == strlen(fpnt+1)) {
389 		fpnt = fname + strlen(fname) - sufflen;
390 		fpnt[sufflen + 2] = '\0';
391 		fpnt[0] = end;
392 		fpnt[1] = beg;
393 
394 		/*  Basename | Suffix
395 		 *  before:
396 		 *  x        | yz
397 		 *  after:
398 		 *  xz       | a.. */
399 		fpnt++;
400 		sufflen++;
401 
402 		/* Reset so we start back at all 'a's in our extended suffix. */
403 		tfnum = 0;
404 		fnum = 0;
405 	}
406 
407 	/* maxfiles = pattlen^sufflen, but don't use libm. */
408 	for (maxfiles = 1, i = 0; i < sufflen; i++)
409 		if (LONG_MAX / pattlen < maxfiles)
410 			errx(EX_USAGE, "suffix is too long (max %ld)", i);
411 		else
412 			maxfiles *= pattlen;
413 
414 	if (fnum == maxfiles)
415 		errx(EX_DATAERR, "too many files");
416 
417 	/* Generate suffix of sufflen letters */
418 	tfnum = fnum;
419 	i = sufflen - 1;
420 	do {
421 		fpnt[i] = tfnum % pattlen + beg;
422 		tfnum /= pattlen;
423 	} while (i-- > 0);
424 	fpnt[sufflen] = '\0';
425 
426 	++fnum;
427 	if ((ofd = open(fname, flags, DEFFILEMODE)) < 0) {
428 		if (!clobber && errno == EEXIST)
429 			goto again;
430 		err(EX_IOERR, "%s", fname);
431 	}
432 	file_open = 1;
433 }
434 
435 static void
436 usage(void)
437 {
438 	(void)fprintf(stderr,
439 "usage: split [-cd] [-l line_count] [-a suffix_length] [file [prefix]]\n"
440 "       split [-cd] -b byte_count[K|k|M|m|G|g] [-a suffix_length] [file [prefix]]\n"
441 "       split [-cd] -n chunk_count [-a suffix_length] [file [prefix]]\n"
442 "       split [-cd] -p pattern [-a suffix_length] [file [prefix]]\n");
443 	exit(EX_USAGE);
444 }
445