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 (5 kb)"
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[] ALIGN_SUFFIX = {
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 = getopt32(argv, "^"
104 "l:b:a:+" /* -a N */
105 "\0" "?2"/*max 2 args*/,
106 &count_p, &count_p, &suffix_len
107 );
108
109 if (opt & SPLIT_OPT_l)
110 cnt = XATOOFF(count_p);
111 if (opt & SPLIT_OPT_b) // FIXME: also needs XATOOFF
112 cnt = xatoull_sfx(count_p,
113 IF_FEATURE_SPLIT_FANCY(split_suffixes)
114 IF_NOT_FEATURE_SPLIT_FANCY(km_suffixes)
115 );
116 sfx = "x";
117
118 argv += optind;
119 if (argv[0]) {
120 int fd;
121 if (argv[1])
122 sfx = argv[1];
123 fd = xopen_stdin(argv[0]);
124 xmove_fd(fd, STDIN_FILENO);
125 } else {
126 argv[0] = (char *) bb_msg_standard_input;
127 }
128
129 if (NAME_MAX < strlen(sfx) + suffix_len)
130 bb_simple_error_msg_and_die("suffix too long");
131
132 {
133 char *char_p = xzalloc(suffix_len + 1);
134 memset(char_p, 'a', suffix_len);
135 pfx = xasprintf("%s%s", sfx, char_p);
136 if (ENABLE_FEATURE_CLEAN_UP)
137 free(char_p);
138 }
139
140 while (1) {
141 bytes_read = safe_read(STDIN_FILENO, read_buffer, READ_BUFFER_SIZE);
142 if (!bytes_read)
143 break;
144 if (bytes_read < 0)
145 bb_simple_perror_msg_and_die(argv[0]);
146 src = read_buffer;
147 do {
148 if (!remaining) {
149 if (!pfx)
150 bb_simple_error_msg_and_die("suffixes exhausted");
151 xmove_fd(xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC), 1);
152 pfx = next_file(pfx, suffix_len);
153 remaining = cnt;
154 }
155
156 if (opt & SPLIT_OPT_b) {
157 /* split by bytes */
158 to_write = (bytes_read < remaining) ? bytes_read : remaining;
159 remaining -= to_write;
160 } else {
161 /* split by lines */
162 /* can be sped up by using _memrchr_
163 * and writing many lines at once... */
164 char *end = memchr(src, '\n', bytes_read);
165 if (end) {
166 --remaining;
167 to_write = end - src + 1;
168 } else {
169 to_write = bytes_read;
170 }
171 }
172
173 xwrite(STDOUT_FILENO, src, to_write);
174 bytes_read -= to_write;
175 src += to_write;
176 } while (bytes_read);
177 }
178 return EXIT_SUCCESS;
179 }
180