summaryrefslogtreecommitdiffhomepage
path: root/coreutils/split.c
blob: dc6f62109df6fdb5911ed5cecc714db779385520 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
/* 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 (5.4 kb)"
//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[] = {
	{ "b", 512 },
	{ "k", 1024 },
	{ "m", 1024*1024 },
	{ "g", 1024*1024*1024 },
	{ "", 0 }
};
#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') {
			*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)
#define SPLIT_OPT_a (1<<2)

int split_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
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;
}