text: /* cmp.c - Compare two files.
   *
   * Copyright 2012 Timothy Elliott <tle@holymonkey.com>
   *
   * See http://opengroup.org/onlinepubs/9699919799/utilities/cmp.html
  
  USE_CMP(NEWTOY(cmp, "<1>2ls(silent)(quiet)[!ls]", TOYFLAG_USR|TOYFLAG_BIN|TOYFLAG_ARGFAIL(2)))
  
  config CMP
    bool "cmp"
    default y
    help
      usage: cmp [-l] [-s] FILE1 [FILE2 [SKIP1 [SKIP2]]]
  
      Compare the contents of two files. (Or stdin and file if only one given.)
  
      -l	Show all differing bytes
      -s	Silent
  */
  
  #define FOR_cmp
  #include "toys.h"
  
  GLOBALS(
    int fd;
    char *name;
  )
  
  static void do_cmp(int fd, char *name)
  {
    int i, len1, len2, min_len, size = sizeof(toybuf)/2;
    long byte_no = 1, line_no = 1;
    char *buf2 = toybuf+size;
  
    // First time through, cache the data and return.
    if (!TT.fd) {
      TT.name = name;
      // On return the old filehandle is closed, and this assures that even
      // if we were called with stdin closed, the new filehandle != 0.
      TT.fd = dup(fd);
      return;
    }
  
    toys.exitval = 0;
  
    for (;;) {
      len1 = readall(TT.fd, toybuf, size);
      len2 = readall(fd, buf2, size);
  
      min_len = len1 < len2 ? len1 : len2;
      for (i=0; i<min_len; i++) {
        if (toybuf[i] != buf2[i]) {
          toys.exitval = 1;
          if (toys.optflags & FLAG_l)
            printf("%ld %o %o\n", byte_no, toybuf[i], buf2[i]);
          else {
            if (!(toys.optflags & FLAG_s)) 
              printf("%s %s differ: char %ld, line %ld\n",
                TT.name, name, byte_no, line_no);
            goto out;
          }
        }
        byte_no++;
        if (toybuf[i] == '\n') line_no++;
      }
      if (len1 != len2) {
        if (!(toys.optflags & FLAG_s))
          fprintf(stderr, "cmp: EOF on %s\n", len1 < len2 ? TT.name : name);
        toys.exitval = 1;
        break;
      }
      if (len1 < 1) break;
    }
  out:
    if (CFG_TOYBOX_FREE) close(TT.fd);
  }
  
  void cmp_main(void)
  {
    toys.exitval = 2;
    loopfiles_rw(toys.optargs, O_CLOEXEC|(WARN_ONLY*!(toys.optflags&FLAG_s)), 0,
      do_cmp);
    if (toys.optc == 1) do_cmp(0, "-");
  }
  