LXR toybox/toys/posix/cmp.c

   1/* cmp.c - Compare two files.
   2 *
   3 * Copyright 2012 Timothy Elliott <tle@holymonkey.com>
   4 *
   5 * See http://opengroup.org/onlinepubs/9699919799/utilities/cmp.html
   6
   7USE_CMP(NEWTOY(cmp, "<1>2ls(silent)(quiet)[!ls]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_ARGFAIL(2)))
   8
   9config CMP
  10  bool "cmp"
  11  default y
  12  help
  13    usage: cmp [-l] [-s] FILE1 [FILE2 [SKIP1 [SKIP2]]]
  14
  15    Compare the contents of two files. (Or stdin and file if only one given.)
  16
  17    -l  Show all differing bytes
  18    -s  Silent
  19*/
  20
  21#define FOR_cmp
  22#include "toys.h"
  23
  24GLOBALS(
  25  int fd;
  26  char *name;
  27)
  28
  29static void do_cmp(int fd, char *name)
  30{
  31  int i, len1, len2, min_len, size = sizeof(toybuf)/2;
  32  long byte_no = 1, line_no = 1;
  33  char *buf2 = toybuf+size;
  34
  35  // First time through, cache the data and return.
  36  if (!TT.fd) {
  37    TT.name = name;
  38    // On return the old filehandle is closed, and this assures that even
  39    // if we were called with stdin closed, the new filehandle != 0.
  40    TT.fd = dup(fd);
  41    return;
  42  }
  43
  44  toys.exitval = 0;
  45
  46  for (;;) {
  47    len1 = readall(TT.fd, toybuf, size);
  48    len2 = readall(fd, buf2, size);
  49
  50    min_len = len1 < len2 ? len1 : len2;
  51    for (i=0; i<min_len; i++) {
  52      if (toybuf[i] != buf2[i]) {
  53        toys.exitval = 1;
  54        if (toys.optflags & FLAG_l)
  55          printf("%ld %o %o\n", byte_no, toybuf[i], buf2[i]);
  56        else {
  57          if (!(toys.optflags & FLAG_s)) 
  58            printf("%s %s differ: char %ld, line %ld\n",
  59              TT.name, name, byte_no, line_no);
  60          goto out;
  61        }
  62      }
  63      byte_no++;
  64      if (toybuf[i] == '\n') line_no++;
  65    }
  66    if (len1 != len2) {
  67      if (!(toys.optflags & FLAG_s))
  68        fprintf(stderr, "cmp: EOF on %s\n", len1 < len2 ? TT.name : name);
  69      toys.exitval = 1;
  70      break;
  71    }
  72    if (len1 < 1) break;
  73  }
  74out:
  75  if (CFG_TOYBOX_FREE) close(TT.fd);
  76}
  77
  78void cmp_main(void)
  79{
  80  toys.exitval = 2;
  81  loopfiles_rw(toys.optargs, O_CLOEXEC|(WARN_ONLY*!(toys.optflags&FLAG_s)), 0,
  82    do_cmp);
  83  if (toys.optc == 1) do_cmp(0, "-");
  84}
  85