LXR busybox/coreutils/split.c

   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/* BB_AUDIT: SUSv3 compliant
   9 * SUSv3 requirements:
  10 * http://www.opengroup.org/onlinepubs/009695399/utilities/split.html
  11 */
  12
  13//usage:#define split_trivial_usage
  14//usage:       "[OPTIONS] [INPUT [PREFIX]]"
  15//usage:#define split_full_usage "\n\n"
  16//usage:       "        -b N[k|m]       Split by N (kilo|mega)bytes"
  17//usage:     "\n        -l N            Split by N lines"
  18//usage:     "\n        -a N            Use N letters as suffix"
  19//usage:
  20//usage:#define split_example_usage
  21//usage:       "$ split TODO foo\n"
  22//usage:       "$ cat TODO | split -a 2 -l 2 TODO_\n"
  23
  24#include "libbb.h"
  25#include "common_bufsiz.h"
  26
  27#if ENABLE_FEATURE_SPLIT_FANCY
  28static const struct suffix_mult split_suffixes[] = {
  29        { "b", 512 },
  30        { "k", 1024 },
  31        { "m", 1024*1024 },
  32        { "g", 1024*1024*1024 },
  33        { "", 0 }
  34};
  35#endif
  36
  37/* Increment the suffix part of the filename.
  38 * Returns NULL if we are out of filenames.
  39 */
  40static char *next_file(char *old, unsigned suffix_len)
  41{
  42        size_t end = strlen(old);
  43        unsigned i = 1;
  44        char *curr;
  45
  46        while (1) {
  47                curr = old + end - i;
  48                if (*curr < 'z') {
  49                        *curr += 1;
  50                        break;
  51                }
  52                i++;
  53                if (i > suffix_len) {
  54                        return NULL;
  55                }
  56                *curr = 'a';
  57        }
  58
  59        return old;
  60}
  61
  62#define read_buffer bb_common_bufsiz1
  63enum { READ_BUFFER_SIZE = COMMON_BUFSIZE - 1 };
  64
  65#define SPLIT_OPT_l (1<<0)
  66#define SPLIT_OPT_b (1<<1)
  67#define SPLIT_OPT_a (1<<2)
  68
  69int split_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  70int split_main(int argc UNUSED_PARAM, char **argv)
  71{
  72        unsigned suffix_len = 2;
  73        char *pfx;
  74        char *count_p;
  75        const char *sfx;
  76        off_t cnt = 1000;
  77        off_t remaining = 0;
  78        unsigned opt;
  79        ssize_t bytes_read, to_write;
  80        char *src;
  81
  82        setup_common_bufsiz();
  83
  84        opt_complementary = "?2:a+"; /* max 2 args; -a N */
  85        opt = getopt32(argv, "l:b:a:", &count_p, &count_p, &suffix_len);
  86
  87        if (opt & SPLIT_OPT_l)
  88                cnt = XATOOFF(count_p);
  89        if (opt & SPLIT_OPT_b) // FIXME: also needs XATOOFF
  90                cnt = xatoull_sfx(count_p,
  91                                IF_FEATURE_SPLIT_FANCY(split_suffixes)
  92                                IF_NOT_FEATURE_SPLIT_FANCY(km_suffixes)
  93                );
  94        sfx = "x";
  95
  96        argv += optind;
  97        if (argv[0]) {
  98                int fd;
  99                if (argv[1])
 100                        sfx = argv[1];
 101                fd = xopen_stdin(argv[0]);
 102                xmove_fd(fd, STDIN_FILENO);
 103        } else {
 104                argv[0] = (char *) bb_msg_standard_input;
 105        }
 106
 107        if (NAME_MAX < strlen(sfx) + suffix_len)
 108                bb_error_msg_and_die("suffix too long");
 109
 110        {
 111                char *char_p = xzalloc(suffix_len + 1);
 112                memset(char_p, 'a', suffix_len);
 113                pfx = xasprintf("%s%s", sfx, char_p);
 114                if (ENABLE_FEATURE_CLEAN_UP)
 115                        free(char_p);
 116        }
 117
 118        while (1) {
 119                bytes_read = safe_read(STDIN_FILENO, read_buffer, READ_BUFFER_SIZE);
 120                if (!bytes_read)
 121                        break;
 122                if (bytes_read < 0)
 123                        bb_simple_perror_msg_and_die(argv[0]);
 124                src = read_buffer;
 125                do {
 126                        if (!remaining) {
 127                                if (!pfx)
 128                                        bb_error_msg_and_die("suffixes exhausted");
 129                                xmove_fd(xopen(pfx, O_WRONLY | O_CREAT | O_TRUNC), 1);
 130                                pfx = next_file(pfx, suffix_len);
 131                                remaining = cnt;
 132                        }
 133
 134                        if (opt & SPLIT_OPT_b) {
 135                                /* split by bytes */
 136                                to_write = (bytes_read < remaining) ? bytes_read : remaining;
 137                                remaining -= to_write;
 138                        } else {
 139                                /* split by lines */
 140                                /* can be sped up by using _memrchr_
 141                                 * and writing many lines at once... */
 142                                char *end = memchr(src, '\n', bytes_read);
 143                                if (end) {
 144                                        --remaining;
 145                                        to_write = end - src + 1;
 146                                } else {
 147                                        to_write = bytes_read;
 148                                }
 149                        }
 150
 151                        xwrite(STDOUT_FILENO, src, to_write);
 152                        bytes_read -= to_write;
 153                        src += to_write;
 154                } while (bytes_read);
 155        }
 156        return EXIT_SUCCESS;
 157}
 158