busybox/coreutils/split.c

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/* vi: set sw=4 ts=4: */
/*
* split - split a file into pieces
* Copyright (c) 2007 Bernhard Reutner-Fischer
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
//config:config SPLIT
//config: bool "split"
//config: default y
//config: help
//config: split a file into pieces.
//config:
//config:config FEATURE_SPLIT_FANCY
//config: bool "Fancy extensions"
//config: default y
//config: depends on SPLIT
//config: help
//config: Add support for features not required by SUSv3.
//config: Supports additional suffixes 'b' for 512 bytes,
//config: 'g' for 1GiB for the -b option.
//applet:IF_SPLIT(APPLET(split, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_SPLIT) += split.o
/* BB_AUDIT: SUSv3 compliant
* SUSv3 requirements:
* http://www.opengroup.org/onlinepubs/009695399/utilities/split.html
*/
//usage:#define split_trivial_usage
//usage: "[OPTIONS] [INPUT [PREFIX]]"
//usage:#define split_full_usage "\n\n"
//usage: " -b N[k|m] Split by N (kilo|mega)bytes"
//usage: "\n -l N Split by N lines"
//usage: "\n -a N Use N letters as suffix"
//usage:
//usage:#define split_example_usage
//usage: "$ split TODO foo\n"
//usage: "$ cat TODO | split -a 2 -l 2 TODO_\n"
#include "libbb.h"
#include "common_bufsiz.h"
#if ENABLE_FEATURE_SPLIT_FANCY
static const struct suffix_mult split_suffixes[] = {
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{ "b", 512 },
{ "k", 1024 },
{ "m", 1024*1024 },
{ "g", 1024*1024*1024 },
{ "", 0 }
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};
#endif
/* Increment the suffix part of the filename.
* Returns NULL if we are out of filenames.
*/
static char *next_file(char *old, unsigned suffix_len)
{
size_t end = strlen(old);
unsigned i = 1;
char *curr;
while (1) {
curr = old + end - i;
if (*curr < 'z') {
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*curr += 1;
break;
}
i++;
if (i > suffix_len) {
return NULL;
}
*curr = 'a';
}
return old;
}
#define read_buffer bb_common_bufsiz1
enum { READ_BUFFER_SIZE = COMMON_BUFSIZE - 1 };
#define SPLIT_OPT_l (1<<0)
#define SPLIT_OPT_b (1<<1)
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#define SPLIT_OPT_a (1<<2)
int split_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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int split_main(int argc UNUSED_PARAM, char **argv)
{
unsigned suffix_len = 2;
char *pfx;
char *count_p;
const char *sfx;
off_t cnt = 1000;
off_t remaining = 0;
unsigned opt;
ssize_t bytes_read, to_write;
char *src;
setup_common_bufsiz();
opt_complementary = "?2"; /* max 2 args; -a N */
opt = getopt32(argv, "l:b:a:+", &count_p, &count_p, &suffix_len);
if (opt & SPLIT_OPT_l)
cnt = XATOOFF(count_p);
if (opt & SPLIT_OPT_b) // FIXME: also needs XATOOFF
cnt = xatoull_sfx(count_p,
IF_FEATURE_SPLIT_FANCY(split_suffixes)
IF_NOT_FEATURE_SPLIT_FANCY(km_suffixes)
);
sfx = "x";
argv += optind;
if (argv[0]) {
int fd;
if (argv[1])
sfx = argv[1];
fd = xopen_stdin(argv[0]);
xmove_fd(fd, STDIN_FILENO);
} else {
argv[0] = (char *) bb_msg_standard_input;
}
if (NAME_MAX < strlen(sfx) + suffix_len)
bb_error_msg_and_die("suffix too long");
{
char *char_p = xzalloc(suffix_len + 1);
memset(char_p, 'a', suffix_len);
pfx = xasprintf("%s%s", sfx, char_p);
if (ENABLE_FEATURE_CLEAN_UP)
free(char_p);
}
while (1) {
bytes_read = safe_read(STDIN_FILENO, read_buffer, READ_BUFFER_SIZE);
if (!bytes_read)
break;
if (bytes_read < 0)
bb_simple_perror_msg_and_die(argv[0]);
src = read_buffer;
do {
if (!remaining) {
if (!pfx)
bb_error_msg_and_die("suffixes exhausted");
xmove_fd(xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC), 1);
pfx = next_file(pfx, suffix_len);
remaining = cnt;
}
if (opt & SPLIT_OPT_b) {
/* split by bytes */
to_write = (bytes_read < remaining) ? bytes_read : remaining;
remaining -= to_write;
} else {
/* split by lines */
/* can be sped up by using _memrchr_
* and writing many lines at once... */
char *end = memchr(src, '\n', bytes_read);
if (end) {
--remaining;
to_write = end - src + 1;
} else {
to_write = bytes_read;
}
}
xwrite(STDOUT_FILENO, src, to_write);
bytes_read -= to_write;
src += to_write;
} while (bytes_read);
}
return EXIT_SUCCESS;
}