coreutils/catv.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * cat -v implementation for busybox
   4  *
   5  * Copyright (C) 2006 Rob Landley <rob@landley.net>
   6  *
   7  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   8  */
   9
  10 /* See "Cat -v considered harmful" at
  11  * http://cm.bell-labs.com/cm/cs/doc/84/kp.ps.gz */
  12
  13 #include "busybox.h"
  14 #include <unistd.h>
  15 #include <fcntl.h>
  16
  17 int catv_main(int argc, char **argv)
  18 {
  19         int retval = EXIT_SUCCESS, fd, flags;
  20
  21         flags = bb_getopt_ulflags(argc, argv, "etv");
  22         flags ^= 4;
  23
  24         // Loop through files.
  25
  26         argv += optind;
  27         do {
  28                 // Read from stdin if there's nothing else to do.
  29
  30                 fd = 0;
  31                 if (*argv && 0>(fd = bb_xopen(*argv, O_RDONLY))) retval = EXIT_FAILURE;
  32                 else for(;;) {
  33                         int i, res;
  34
  35                         res = read(fd, bb_common_bufsiz1, sizeof(bb_common_bufsiz1));
  36                         if (res < 0) retval = EXIT_FAILURE;
  37                         if (res <1) break;
  38                         for (i=0; i<res; i++) {
  39                                 char c=bb_common_bufsiz1[i];
  40
  41                                 if (c > 126 && (flags & 4)) {
  42                                         if (c == 127) {
  43                                                 printf("^?");
  44                                                 continue;
  45                                         } else {
  46                                                 printf("M-");
  47                                                 c -= 128;
  48                                         }
  49                                 }
  50                                 if (c < 32) {
  51                                         if (c == 10) {
  52                                            if (flags & 1) putchar('$');
  53                                         } else if (flags & (c==9 ? 2 : 4)) {
  54                                                 printf("^%c", c+'@');
  55                                                 continue;
  56                                         }
  57                                 }
  58                                 putchar(c);
  59                         }
  60                 }
  61                 if (ENABLE_FEATURE_CLEAN_UP && fd) close(fd);
  62         } while (*++argv);
  63
  64         return retval;
  65 }