/*-
* SPDX-License-Identifier: BSD-2-Clause
*
* Copyright (c) 2002 Tim J. Robbins.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
/*
* csplit -- split files based on context
*
* This utility splits its input into numbered output files by line number
* or by a regular expression. Regular expression matches have an optional
* offset with them, allowing the split to occur a specified number of
* lines before or after the match.
*
* To handle negative offsets, we stop reading when the match occurs and
* store the offset that the file should have been split at, then use
* this output file as input until all the "overflowed" lines have been read.
* The file is then closed and truncated to the correct length.
*
* We assume that the output files can be seeked upon (ie. they cannot be
* symlinks to named pipes or character devices), but make no such
* assumption about the input.
*/
#include <sys/cdefs.h>
#include <sys/types.h>
#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <limits.h>
#include <locale.h>
#include <regex.h>
#include <signal.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
static void cleanup(void);
static void do_lineno(const char *);
static void do_rexp(const char *);
static char *get_line(void);
static void handlesig(int);
static FILE *newfile(void);
static void toomuch(FILE *, long);
static void usage(void);
/*
* Command line options
*/
static const char *prefix; /* File name prefix */
static long sufflen; /* Number of decimal digits for suffix */
static int sflag; /* Suppress output of file names */
static int kflag; /* Keep output if error occurs */
/*
* Other miscellaneous globals (XXX too many)
*/
static long lineno; /* Current line number in input file */
static long reps; /* Number of repetitions for this pattern */
static long nfiles; /* Number of files output so far */
static long maxfiles; /* Maximum number of files we can create */
static char currfile[PATH_MAX]; /* Current output file */
static const char *infn; /* Name of the input file */
static FILE *infile; /* Input file handle */
static FILE *overfile; /* Overflow file for toomuch() */
static off_t truncofs; /* Offset this file should be truncated at */
static int doclean; /* Should cleanup() remove output? */
int
main(int argc, char *argv[])
{
struct sigaction sa;
long i;
int ch;
const char *expr;
char *ep, *p;
FILE *ofp;
setlocale(LC_ALL, "");
kflag = sflag = 0;
prefix = "xx";
sufflen = 2;
while ((ch = getopt(argc, argv, "ksf:n:")) > 0) {
switch (ch) {
case 'f':
prefix = optarg;
break;
case 'k':
kflag = 1;
break;
case 'n':
errno = 0;
sufflen = strtol(optarg, &ep, 10);
if (sufflen <= 0 || *ep != '\0' || errno != 0)
errx(1, "%s: bad suffix length", optarg);
break;
case 's':
sflag = 1;
break;
default:
usage();
/*NOTREACHED*/
}
}
if (sufflen + strlen(prefix) >= PATH_MAX)
errx(1, "name too long");
argc -= optind;
argv += optind;
if ((infn = *argv++) == NULL)
usage();
if (strcmp(infn, "-") == 0) {
infile = stdin;
infn = "stdin";
} else if ((infile = fopen(infn, "r")) == NULL)
err(1, "%s", infn);
if (!kflag) {
doclean = 1;
atexit(cleanup);
sa.sa_flags = 0;
sa.sa_handler = handlesig;
sigemptyset(&sa.sa_mask);
sigaddset(&sa.sa_mask, SIGHUP);
sigaddset(&sa.sa_mask, SIGINT);
sigaddset(&sa.sa_mask, SIGTERM);
sigaction(SIGHUP, &sa, NULL);
sigaction(SIGINT, &sa, NULL);
sigaction(SIGTERM, &sa, NULL);
}
lineno = 0;
nfiles = 0;
truncofs = 0;
overfile = NULL;
/* Ensure 10^sufflen < LONG_MAX. */
for (maxfiles = 1, i = 0; i < sufflen; i++) {
if (maxfiles > LONG_MAX / 10)
errx(1, "%ld: suffix too long (limit %ld)",
sufflen, i);
maxfiles *= 10;
}
/* Create files based on supplied patterns. */
while (nfiles < maxfiles - 1 && (expr = *argv++) != NULL) {
/* Look ahead & see if this pattern has any repetitions. */
if (*argv != NULL && **argv == '{') {
errno = 0;
reps = strtol(*argv + 1, &ep, 10);
if (reps < 0 || *ep != '}' || errno != 0)
errx(1, "%s: bad repetition count", *argv + 1);
argv++;
} else
reps = 0;
if (*expr == '/' || *expr == '%') {
do
do_rexp(expr);
while (reps-- != 0 && nfiles < maxfiles - 1);
} else if (isdigit((unsigned char)*expr))
do_lineno(expr);
else
errx(1, "%s: unrecognised pattern", expr);
}
/* Copy the rest into a new file. */
if (!feof(infile)) {
ofp = newfile();
while ((p = get_line()) != NULL && fputs(p, ofp) != EOF)
;
if (!sflag)
printf("%jd\n", (intmax_t)ftello(ofp));
if (fclose(ofp) != 0)
err(1, "%s", currfile);
}
toomuch(NULL, 0);
doclean = 0;
return (0);
}
static void
usage(void)
{
fprintf(stderr,
"usage: csplit [-ks] [-f prefix] [-n number] file args ...\n");
exit(1);
}
static void
handlesig(int sig __unused)
{
const char msg[] = "csplit: caught signal, cleaning up\n";
write(STDERR_FILENO, msg, sizeof(msg) - 1);
cleanup();
_exit(2);
}
/* Create a new output file. */
static FILE *
newfile(void)
{
FILE *fp;
if ((size_t)snprintf(currfile, sizeof(currfile), "%s%0*ld", prefix,
(int)sufflen, nfiles) >= sizeof(currfile))
errc(1, ENAMETOOLONG, NULL);
if ((fp = fopen(currfile, "w+")) == NULL)
err(1, "%s", currfile);
nfiles++;
return (fp);
}
/* Remove partial output, called before exiting. */
static void
cleanup(void)
{
char fnbuf[PATH_MAX];
long i;
if (!doclean)
return;
/*
* NOTE: One cannot portably assume to be able to call snprintf()
* from inside a signal handler. It does, however, appear to be safe
* to do on FreeBSD. The solution to this problem is worse than the
* problem itself.
*/
for (i = 0; i < nfiles; i++) {
snprintf(fnbuf, sizeof(fnbuf), "%s%0*ld", prefix,
(int)sufflen, i);
unlink(fnbuf);
}
}
/* Read a line from the input into a static buffer. */
static char *
get_line(void)
{
static char lbuf[LINE_MAX];
FILE *src;
src = overfile != NULL ? overfile : infile;
again: if (fgets(lbuf, sizeof(lbuf), src) == NULL) {
if (src == overfile) {
src = infile;
goto again;
}
return (NULL);
}
if (ferror(src))
err(1, "%s", infn);
lineno++;
return (lbuf);
}
/* Conceptually rewind the input (as obtained by get_line()) back `n' lines. */
static void
toomuch(FILE *ofp, long n)
{
char buf[BUFSIZ];
size_t i, nread;
if (overfile != NULL) {
/*
* Truncate the previous file we overflowed into back to
* the correct length, close it.
*/
if (fflush(overfile) != 0)
err(1, "overflow");
if (ftruncate(fileno(overfile), truncofs) != 0)
err(1, "overflow");
if (fclose(overfile) != 0)
err(1, "overflow");
overfile = NULL;
}
if (n == 0)
/* Just tidying up */
return;
lineno -= n;
/*
* Wind the overflow file backwards to `n' lines before the
* current one.
*/
do {
if (ftello(ofp) < (off_t)sizeof(buf))
rewind(ofp);
else
fseeko(ofp, -(off_t)sizeof(buf), SEEK_CUR);
if (ferror(ofp))
errx(1, "%s: can't seek", currfile);
if ((nread = fread(buf, 1, sizeof(buf), ofp)) == 0)
errx(1, "can't read overflowed output");
if (fseeko(ofp, -(off_t)nread, SEEK_CUR) != 0)
err(1, "%s", currfile);
for (i = 1; i <= nread; i++)
if (buf[nread - i] == '\n' && n-- == 0)
break;
if (ftello(ofp) == 0)
break;
} while (n > 0);
if (fseeko(ofp, nread - i + 1, SEEK_CUR) != 0)
err(1, "%s", currfile);
/*
* get_line() will read from here. Next call will truncate to
* truncofs in this file.
*/
overfile = ofp;
truncofs = ftello(overfile);
}
/* Handle splits for /regexp/ and %regexp% patterns. */
static void
do_rexp(const char *expr)
{
regex_t cre;
intmax_t nwritten;
long ofs;
int first;
char *ecopy, *ep, *p, *pofs, *re;
FILE *ofp;
if ((ecopy = strdup(expr)) == NULL)
err(1, "strdup");
re = ecopy + 1;
if ((pofs = strrchr(ecopy, *expr)) == NULL || pofs[-1] == '\\')
errx(1, "%s: missing trailing %c", expr, *expr);
*pofs++ = '\0';
if (*pofs != '\0') {
errno = 0;
ofs = strtol(pofs, &ep, 10);
if (*ep != '\0' || errno != 0)
errx(1, "%s: bad offset", pofs);
} else
ofs = 0;
if (regcomp(&cre, re, REG_BASIC|REG_NOSUB) != 0)
errx(1, "%s: bad regular expression", re);
if (*expr == '/')
/* /regexp/: Save results to a file. */
ofp = newfile();
else {
/* %regexp%: Make a temporary file for overflow. */
if ((ofp = tmpfile()) == NULL)
err(1, "tmpfile");
}
/* Read and output lines until we get a match. */
first = 1;
while ((p = get_line()) != NULL) {
if (fputs(p, ofp) == EOF)
break;
if (!first && regexec(&cre, p, 0, NULL, 0) == 0)
break;
first = 0;
}
if (p == NULL) {
toomuch(NULL, 0);
errx(1, "%s: no match", re);
}
if (ofs <= 0) {
/*
* Negative (or zero) offset: throw back any lines we should
* not have read yet.
*/
if (p != NULL) {
toomuch(ofp, -ofs + 1);
nwritten = (intmax_t)truncofs;
} else
nwritten = (intmax_t)ftello(ofp);
} else {
/*
* Positive offset: copy the requested number of lines
* after the match.
*/
while (--ofs > 0 && (p = get_line()) != NULL)
fputs(p, ofp);
toomuch(NULL, 0);
nwritten = (intmax_t)ftello(ofp);
if (fclose(ofp) != 0)
err(1, "%s", currfile);
}
if (!sflag && *expr == '/')
printf("%jd\n", nwritten);
regfree(&cre);
free(ecopy);
}
/* Handle splits based on line number. */
static void
do_lineno(const char *expr)
{
long lastline, tgtline;
char *ep, *p;
FILE *ofp;
errno = 0;
tgtline = strtol(expr, &ep, 10);
if (tgtline <= 0 || errno != 0 || *ep != '\0')
errx(1, "%s: bad line number", expr);
lastline = tgtline;
if (lastline <= lineno)
errx(1, "%s: can't go backwards", expr);
while (nfiles < maxfiles - 1) {
ofp = newfile();
while (lineno + 1 != lastline) {
if ((p = get_line()) == NULL)
errx(1, "%ld: out of range", lastline);
if (fputs(p, ofp) == EOF)
break;
}
if (!sflag)
printf("%jd\n", (intmax_t)ftello(ofp));
if (fclose(ofp) != 0)
err(1, "%s", currfile);
if (reps-- == 0)
break;
lastline += tgtline;
}
}
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