* Copyright (c) 1987, 1993, 1994

/* $NetBSD: split.c,v 1.33 2024/02/09 22:08:38 andvar Exp $ */

/*
* Copyright (c) 1987, 1993, 1994
* The Regents of the University of California. 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.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1987, 1993, 1994\
The Regents of the University of California. All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "@(#)split.c 8.3 (Berkeley) 4/25/94";
#endif
__RCSID("$NetBSD: split.c,v 1.33 2024/02/09 22:08:38 andvar Exp $");
#endif /* not lint */

#include <sys/param.h>
#include <sys/stat.h>

#include <ctype.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#define DEFLINE 1000 /* Default num lines per file. */

static int file_open; /* If a file is open. */
static int ifd = STDIN_FILENO, ofd = -1; /* Input/output file descriptors. */
static char *fname; /* File name prefix. */
static size_t sfxlen = 2; /* Suffix length. */
static int autosfx = 1; /* Whether to auto-extend the suffix length. */

static void newfile(void);
static void split1(off_t, int) __dead;
static void split2(off_t) __dead;
static void split3(off_t) __dead;
static void usage(void) __dead;
static size_t bigwrite(int, void const *, size_t);

int
main(int argc, char *argv[])
{
int ch;
char *ep, *p;
char const *base;
off_t bytecnt = 0; /* Byte count to split on. */
off_t numlines = 0; /* Line count to split on. */
off_t chunks = 0; /* Number of chunks to split into. */

while ((ch = getopt(argc, argv, "0123456789a:b:l:n:")) != -1)
switch (ch) {
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
/*
* Undocumented kludge: split was originally designed
* to take a number after a dash.
*/
if (numlines == 0) {
p = argv[optind - 1];
if (p[0] == '-' && p[1] == ch && !p[2])
p++;
else
p = argv[optind] + 1;
numlines = strtoull(p, &ep, 10);
if (numlines == 0 || *ep != '\0')
errx(EXIT_FAILURE, "%s: illegal line count.", p);
}
break;
case 'a': /* Suffix length. */
if (!isdigit((unsigned char)optarg[0]) ||
(sfxlen = (size_t)strtoul(optarg, &ep, 10)) == 0 ||
*ep != '\0')
errx(EXIT_FAILURE, "%s: illegal suffix length.", optarg);
autosfx = 0;
break;
case 'b': /* Byte count. */
if (!isdigit((unsigned char)optarg[0]) ||
(bytecnt = strtoull(optarg, &ep, 10)) == 0 ||
(*ep != '\0' && *ep != 'k' && *ep != 'm'))
errx(EXIT_FAILURE, "%s: illegal byte count.", optarg);
if (*ep == 'k')
bytecnt *= 1024;
else if (*ep == 'm')
bytecnt *= 1024 * 1024;
break;
case 'l': /* Line count. */
if (numlines != 0)
usage();
if (!isdigit((unsigned char)optarg[0]) ||
(numlines = strtoull(optarg, &ep, 10)) == 0 ||
*ep != '\0')
errx(EXIT_FAILURE, "%s: illegal line count.", optarg);
break;
case 'n': /* Chunks. */
if (!isdigit((unsigned char)optarg[0]) ||
(chunks = (size_t)strtoul(optarg, &ep, 10)) == 0 ||
*ep != '\0')
errx(EXIT_FAILURE, "%s: illegal number of chunks.", optarg);
break;
default:
usage();
}
argv += optind;
argc -= optind;

if (*argv != NULL) {
if (strcmp(*argv, "-") != 0 &&
(ifd = open(*argv, O_RDONLY, 0)) < 0)
err(EXIT_FAILURE, "%s", *argv);
++argv;
}

base = (*argv != NULL) ? *argv++ : "x";
if ((fname = malloc(strlen(base) + sfxlen + 1)) == NULL)
err(EXIT_FAILURE, NULL);
(void)strcpy(fname, base); /* File name prefix. */

if (*argv != NULL)
usage();

if (numlines == 0)
numlines = DEFLINE;
else if (bytecnt || chunks)
usage();

if (bytecnt && chunks)
usage();

if (bytecnt)
split1(bytecnt, 0);
else if (chunks)
split3(chunks);
else
split2(numlines);

return 0;
}

/*
* split1 --
* Split the input by bytes.
*/
static void
split1(off_t bytecnt, int maxcnt)
{
off_t bcnt;
ssize_t dist, len;
char *C;
char bfr[MAXBSIZE];
int nfiles;

nfiles = 0;

for (bcnt = 0;;)
switch (len = read(ifd, bfr, MAXBSIZE)) {
case 0:
exit(EXIT_SUCCESS);
/* NOTREACHED */
case -1:
err(EXIT_FAILURE, "read");
/* NOTREACHED */
default:
if (!file_open) {
if (!maxcnt || (nfiles < maxcnt)) {
newfile();
nfiles++;
file_open = 1;
}
}
if (bcnt + len >= bytecnt) {
/* LINTED: bytecnt - bcnt <= len */
dist = bytecnt - bcnt;
if (bigwrite(ofd, bfr, dist) != (size_t)dist)
err(EXIT_FAILURE, "write");
len -= dist;
for (C = bfr + dist; len >= bytecnt;
/* LINTED: bytecnt <= len */
len -= bytecnt, C += bytecnt) {
if (!maxcnt || (nfiles < maxcnt)) {
newfile();
nfiles++;
}
/* LINTED: as above */
if (bigwrite(ofd,
C, bytecnt) != (size_t)bytecnt)
err(EXIT_FAILURE, "write");
}
if (len) {
if (!maxcnt || (nfiles < maxcnt)) {
newfile();
nfiles++;
}
/* LINTED: len >= 0 */
if (bigwrite(ofd, C, len) != (size_t)len)
err(EXIT_FAILURE, "write");
} else
file_open = 0;
bcnt = len;
} else {
bcnt += len;
/* LINTED: len >= 0 */
if (bigwrite(ofd, bfr, len) != (size_t)len)
err(EXIT_FAILURE, "write");
}
}
}

/*
* split2 --
* Split the input by lines.
*/
static void
split2(off_t numlines)
{
off_t lcnt;
size_t bcnt;
ssize_t len;
char *Ce, *Cs;
char bfr[MAXBSIZE];

for (lcnt = 0;;)
switch (len = read(ifd, bfr, MAXBSIZE)) {
case 0:
exit(EXIT_SUCCESS);
/* NOTREACHED */
case -1:
err(EXIT_FAILURE, "read");
/* NOTREACHED */
default:
if (!file_open) {
newfile();
file_open = 1;
}
for (Cs = Ce = bfr; len--; Ce++)
if (*Ce == '\n' && ++lcnt == numlines) {
bcnt = Ce - Cs + 1;
if (bigwrite(ofd, Cs, bcnt) != (size_t)bcnt)
err(EXIT_FAILURE, "write");
lcnt = 0;
Cs = Ce + 1;
if (len)
newfile();
else
file_open = 0;
}
if (Cs < Ce) {
bcnt = Ce - Cs;
if (bigwrite(ofd, Cs, bcnt) != (size_t)bcnt)
err(EXIT_FAILURE, "write");
}
}
}

/*
* split3 --
* Split the input into specified number of chunks
*/
static void
split3(off_t chunks)
{
struct stat sb;

if (fstat(ifd, &sb) == -1) {
err(EXIT_FAILURE, "stat");
/* NOTREACHED */
}

if (chunks > sb.st_size) {
errx(EXIT_FAILURE, "can't split into more than %d files",
(int)sb.st_size);
/* NOTREACHED */
}

split1(sb.st_size/chunks, chunks);
}

/*
* newfile --
* Open a new output file.
*/
static void
newfile(void)
{
static int fnum;
static char *fpnt;
int quot, i;

if (ofd == -1) {
fpnt = fname + strlen(fname);
fpnt[sfxlen] = '\0';
} else if (close(ofd) != 0)
err(EXIT_FAILURE, "%s", fname);

quot = fnum;

/* If '-a' is not specified, then we automatically expand the
* suffix length to accommodate splitting all input. We do this
* by moving the suffix pointer (fpnt) forward and incrementing
* sfxlen by one, thereby yielding an additional two characters
* and allowing all output files to sort such that 'cat *' yields
* the input in order. I.e., the order is '... xyy xyz xzaaa
* xzaab ... xzyzy, xzyzz, xzzaaaa, xzzaaab' and so on. */
if (autosfx && (fpnt[0] == 'y') && (strspn(fpnt+1, "z") == strlen(fpnt+1))) {
if ((fname = realloc(fname, strlen(fname) + sfxlen + 2 + 1)) == NULL)
err(EXIT_FAILURE, NULL);
/* NOTREACHED */

fpnt = fname + strlen(fname) - sfxlen;
fpnt[sfxlen + 2] = '\0';

fpnt[0] = 'z';
fpnt[1] = 'a';

/* Basename | Suffix
* before:
* x | yz
* after:
* xz | a.. */
fpnt++;
sfxlen++;

/* Reset so we start back at all 'a's in our extended suffix. */
quot = 0;
fnum = 0;
}

for (i = sfxlen - 1; i >= 0; i--) {
fpnt[i] = quot % 26 + 'a';
quot = quot / 26;
}
if (quot > 0)
errx(EXIT_FAILURE, "too many files.");
++fnum;
if ((ofd = open(fname, O_WRONLY | O_CREAT | O_TRUNC, DEFFILEMODE)) < 0)
err(EXIT_FAILURE, "%s", fname);
}

static size_t
bigwrite(int fd, const void *buf, size_t len)
{
const char *ptr = buf;
size_t sofar = 0;
ssize_t w;

while (len != 0) {
if ((w = write(fd, ptr, len)) == -1)
return sofar;
len -= w;
ptr += w;
sofar += w;
}
return sofar;
}

static void
usage(void)
{
(void)fprintf(stderr,
"usage: %s [-b byte_count] [-l line_count] [-n chunk_count] [-a suffix_length] "
"[file [prefix]]\n", getprogname());
exit(EXIT_FAILURE);
}