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