LXR toybox/toys/posix/split.c

   1/* split.c - split a file into smaller files
   2 *
   3 * Copyright 2013 Rob Landley <rob@landley.net>
   4 *
   5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/split.html
   6 *
   7 * Standard does not cover:
   8 * - should splitting an empty file produce an empty outfile? (Went with "no".)
   9 * - permissions on output file
  10
  11USE_SPLIT(NEWTOY(split, ">2a#<1=2>9b#<1l#<1[!bl]", TOYFLAG_USR|TOYFLAG_BIN))
  12
  13config SPLIT
  14  bool "split"
  15  default y
  16  help
  17    usage: split [-a SUFFIX_LEN] [-b BYTES] [-l LINES] [INPUT [OUTPUT]]
  18
  19    Copy INPUT (or stdin) data to a series of OUTPUT (or "x") files with
  20    alphabetically increasing suffix (aa, ab, ac... az, ba, bb...).
  21
  22    -a  Suffix length (default 2)
  23    -b  BYTES/file (10, 10k, 10m, 10g...)
  24    -l  LINES/file (default 1000)
  25*/
  26
  27#define FOR_split
  28#include "toys.h"
  29
  30GLOBALS(
  31  long lines;
  32  long bytes;
  33  long suflen;
  34
  35  char *outfile;
  36)
  37
  38static void do_split(int infd, char *in)
  39{
  40  unsigned long bytesleft, linesleft, filenum, len, pos;
  41  int outfd = -1;
  42  struct stat st;
  43
  44  // posix doesn't cover permissions on output file, so copy input (or 0777)
  45  st.st_mode = 0777;
  46  fstat(infd, &st);
  47
  48  len = pos = filenum = bytesleft = linesleft = 0;
  49  for (;;) {
  50    int i, j;
  51
  52    // Refill toybuf?
  53    if (len == pos) {
  54      if (!(len = xread(infd, toybuf, sizeof(toybuf)))) break;
  55      pos = 0;
  56    }
  57
  58    // Start new output file?
  59    if ((TT.bytes && !bytesleft) || (TT.lines && !linesleft)) {
  60      char *s = TT.outfile + strlen(TT.outfile);
  61
  62      j = filenum++;
  63      for (i = 0; i<TT.suflen; i++) {
  64        *(--s) = 'a'+(j%26);
  65        j /= 26;
  66      }
  67      if (j) error_exit("bad suffix");
  68      bytesleft = TT.bytes;
  69      linesleft = TT.lines;
  70      if (outfd != -1) close(outfd);
  71      outfd = xcreate(TT.outfile, O_RDWR|O_CREAT|O_TRUNC, st.st_mode & 0777);
  72    }
  73
  74    // Write next chunk of output.
  75    if (TT.lines) {
  76      for (i = pos; i < len; ) {
  77        if (toybuf[i++] == '\n' && !--linesleft) break;
  78        if (!--bytesleft) break;
  79      }
  80      j = i - pos;
  81    } else {
  82      j = len - pos;
  83      if (j > bytesleft) j = bytesleft;
  84      bytesleft -= j;
  85    }
  86    xwrite(outfd, toybuf+pos, j);
  87    pos += j;
  88  }
  89
  90  if (CFG_TOYBOX_FREE) {
  91    if (outfd != -1) close(outfd);
  92    if (infd) close(infd);
  93    free(TT.outfile);
  94  }
  95  xexit();
  96}
  97
  98void split_main(void)
  99{
 100  if (!TT.bytes && !TT.lines) TT.lines = 1000;
 101
 102  // Allocate template for output filenames
 103  TT.outfile = xmprintf("%s%*c", (toys.optc == 2) ? toys.optargs[1] : "x",
 104    (int)TT.suflen, ' ');
 105
 106  // We only ever use one input, but this handles '-' or no input for us.
 107  loopfiles(toys.optargs, do_split);
 108}
 109