1 /* vi: set sw=4 ts=4: */
2 /*
3 * split - split a file into pieces
4 * Copyright (c) 2007 Bernhard Reutner-Fischer
5 *
6 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
7 */
8 //config:config SPLIT
9 //config: bool "split"
10 //config: default y
11 //config: help
12 //config: split a file into pieces.
13 //config:
14 //config:config FEATURE_SPLIT_FANCY
15 //config: bool "Fancy extensions"
16 //config: default y
17 //config: depends on SPLIT
18 //config: help
19 //config: Add support for features not required by SUSv3.
20 //config: Supports additional suffixes 'b' for 512 bytes,
21 //config: 'g' for 1GiB for the -b option.
22
23 //applet:IF_SPLIT(APPLET(split, BB_DIR_USR_BIN, BB_SUID_DROP))
24
25 //kbuild:lib-$(CONFIG_SPLIT) += split.o
26
27 /* BB_AUDIT: SUSv3 compliant
28 * SUSv3 requirements:
29 * http://www.opengroup.org/onlinepubs/009695399/utilities/split.html
30 */
31
32 //usage:#define split_trivial_usage
33 //usage: "[OPTIONS] [INPUT [PREFIX]]"
34 //usage:#define split_full_usage "\n\n"
35 //usage: " -b N[k|m] Split by N (kilo|mega)bytes"
36 //usage: "\n -l N Split by N lines"
37 //usage: "\n -a N Use N letters as suffix"
38 //usage:
39 //usage:#define split_example_usage
40 //usage: "$ split TODO foo\n"
41 //usage: "$ cat TODO | split -a 2 -l 2 TODO_\n"
42
43 #include "libbb.h"
44 #include "common_bufsiz.h"
45
46 #if ENABLE_FEATURE_SPLIT_FANCY
47 static const struct suffix_mult split_suffixes[] = {
48 { "b", 512 },
49 { "k", 1024 },
50 { "m", 1024*1024 },
51 { "g", 1024*1024*1024 },
52 { "", 0 }
53 };
54 #endif
55
56 /* Increment the suffix part of the filename.
57 * Returns NULL if we are out of filenames.
58 */
next_file(char * old,unsigned suffix_len)59 static char *next_file(char *old, unsigned suffix_len)
60 {
61 size_t end = strlen(old);
62 unsigned i = 1;
63 char *curr;
64
65 while (1) {
66 curr = old + end - i;
67 if (*curr < 'z') {
68 *curr += 1;
69 break;
70 }
71 i++;
72 if (i > suffix_len) {
73 return NULL;
74 }
75 *curr = 'a';
76 }
77
78 return old;
79 }
80
81 #define read_buffer bb_common_bufsiz1
82 enum { READ_BUFFER_SIZE = COMMON_BUFSIZE - 1 };
83
84 #define SPLIT_OPT_l (1<<0)
85 #define SPLIT_OPT_b (1<<1)
86 #define SPLIT_OPT_a (1<<2)
87
88 int split_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
split_main(int argc UNUSED_PARAM,char ** argv)89 int split_main(int argc UNUSED_PARAM, char **argv)
90 {
91 unsigned suffix_len = 2;
92 char *pfx;
93 char *count_p;
94 const char *sfx;
95 off_t cnt = 1000;
96 off_t remaining = 0;
97 unsigned opt;
98 ssize_t bytes_read, to_write;
99 char *src;
100
101 setup_common_bufsiz();
102
103 opt_complementary = "?2"; /* max 2 args; -a N */
104 opt = getopt32(argv, "l:b:a:+", &count_p, &count_p, &suffix_len);
105
106 if (opt & SPLIT_OPT_l)
107 cnt = XATOOFF(count_p);
108 if (opt & SPLIT_OPT_b) // FIXME: also needs XATOOFF
109 cnt = xatoull_sfx(count_p,
110 IF_FEATURE_SPLIT_FANCY(split_suffixes)
111 IF_NOT_FEATURE_SPLIT_FANCY(km_suffixes)
112 );
113 sfx = "x";
114
115 argv += optind;
116 if (argv[0]) {
117 int fd;
118 if (argv[1])
119 sfx = argv[1];
120 fd = xopen_stdin(argv[0]);
121 xmove_fd(fd, STDIN_FILENO);
122 } else {
123 argv[0] = (char *) bb_msg_standard_input;
124 }
125
126 if (NAME_MAX < strlen(sfx) + suffix_len)
127 bb_error_msg_and_die("suffix too long");
128
129 {
130 char *char_p = xzalloc(suffix_len + 1);
131 memset(char_p, 'a', suffix_len);
132 pfx = xasprintf("%s%s", sfx, char_p);
133 if (ENABLE_FEATURE_CLEAN_UP)
134 free(char_p);
135 }
136
137 while (1) {
138 bytes_read = safe_read(STDIN_FILENO, read_buffer, READ_BUFFER_SIZE);
139 if (!bytes_read)
140 break;
141 if (bytes_read < 0)
142 bb_simple_perror_msg_and_die(argv[0]);
143 src = read_buffer;
144 do {
145 if (!remaining) {
146 if (!pfx)
147 bb_error_msg_and_die("suffixes exhausted");
148 xmove_fd(xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC), 1);
149 pfx = next_file(pfx, suffix_len);
150 remaining = cnt;
151 }
152
153 if (opt & SPLIT_OPT_b) {
154 /* split by bytes */
155 to_write = (bytes_read < remaining) ? bytes_read : remaining;
156 remaining -= to_write;
157 } else {
158 /* split by lines */
159 /* can be sped up by using _memrchr_
160 * and writing many lines at once... */
161 char *end = memchr(src, '\n', bytes_read);
162 if (end) {
163 --remaining;
164 to_write = end - src + 1;
165 } else {
166 to_write = bytes_read;
167 }
168 }
169
170 xwrite(STDOUT_FILENO, src, to_write);
171 bytes_read -= to_write;
172 src += to_write;
173 } while (bytes_read);
174 }
175 return EXIT_SUCCESS;
176 }
177