summaryrefslogtreecommitdiff
path: root/coreutils/split.c
blob: 51a631c563944837d3fdc1a748aeabb72245d34d (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
/* vi: set sw=4 ts=4: */
/*
 * split - split a file into pieces
 * Copyright (c) 2007 Bernhard Fischer
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */
/* BB_AUDIT: SUSv3 compliant
 * SUSv3 requirements:
 * http://www.opengroup.org/onlinepubs/009695399/utilities/split.html
 */
#include "libbb.h"

static const struct suffix_mult split_suffices[] = {
#if ENABLE_FEATURE_SPLIT_FANCY
	{ "b", 512 },
#endif
	{ "k", 1024 },
	{ "m", 1024*1024 },
#if ENABLE_FEATURE_SPLIT_FANCY
	{ "g", 1024*1024*1024 },
#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;

	do {
		curr = old + end - i;
		if (*curr < 'z') {
			*curr += 1;
			break;
		}
		i++;
		if (i > suffix_len) {
			return NULL;
		}
		*curr = 'a';
	} while (1);

	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, 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;

	opt_complementary = "?2";
	opt = getopt32(argv, "l:b:a:", &count_p, &count_p, &sfx);

	if (opt & SPLIT_OPT_l)
		cnt = xatoul(count_p);
	if (opt & SPLIT_OPT_b)
		cnt = xatoul_sfx(count_p, split_suffices);
	if (opt & SPLIT_OPT_a)
		suffix_len = xatou(sfx);
	sfx = "x";

	argv += optind;
	if (argv[0]) {
		if (argv[1])
			sfx = argv[1];
		xmove_fd(xopen(argv[0], O_RDONLY), 0);
	} 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(0, 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(1, src, to_write);
			bytes_read -= to_write;
			src += to_write;
		} while (bytes_read);
	}
	return 0;
}