diff options
Diffstat (limited to 'usr.bin/csplit/csplit.c')
| -rw-r--r-- | usr.bin/csplit/csplit.c | 467 |
1 files changed, 467 insertions, 0 deletions
diff --git a/usr.bin/csplit/csplit.c b/usr.bin/csplit/csplit.c new file mode 100644 index 0000000..7143d73 --- /dev/null +++ b/usr.bin/csplit/csplit.c @@ -0,0 +1,467 @@ +/*- + * 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> +__FBSDID("$FreeBSD$"); + +#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 *getline(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 = getline()) != NULL && fputs(p, ofp) == 0) + ; + 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 * +getline(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 getline()) 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); + + /* + * getline() 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 = getline()) != NULL) { + if (fputs(p, ofp) != 0) + break; + if (!first && regexec(&cre, p, 0, NULL, 0) == 0) + break; + first = 0; + } + + if (p == NULL) + 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 = getline()) != 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 = getline()) == NULL) + errx(1, "%ld: out of range", lastline); + if (fputs(p, ofp) != 0) + break; + } + if (!sflag) + printf("%jd\n", (intmax_t)ftello(ofp)); + if (fclose(ofp) != 0) + err(1, "%s", currfile); + if (reps-- == 0) + break; + lastline += tgtline; + } +} |
