release/src/router/busybox/coreutils/cat.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * cat implementation for busybox
   4  *
   5  * Copyright (C) 2003  Manuel Novoa III  <mjn3@codepoet.org>
   6  *
   7  * Licensed under GPLv2, see file LICENSE in this source tree.
   8  */
   9
  10 /* BB_AUDIT SUSv3 compliant */
  11 /* http://www.opengroup.org/onlinepubs/007904975/utilities/cat.html */
  12
  13 //kbuild:lib-$(CONFIG_CAT)     += cat.o
  14 //kbuild:lib-$(CONFIG_MORE)    += cat.o # more uses it if stdout isn't a tty
  15 //kbuild:lib-$(CONFIG_LESS)    += cat.o # less too
  16 //kbuild:lib-$(CONFIG_CRONTAB) += cat.o # crontab -l
  17
  18 //config:config CAT
  19 //config:       bool "cat"
  20 //config:       default y
  21 //config:       help
  22 //config:         cat is used to concatenate files and print them to the standard
  23 //config:         output. Enable this option if you wish to enable the 'cat' utility.
  24
  25 //usage:#define cat_trivial_usage
  26 //usage:       "[FILE]..."
  27 //usage:#define cat_full_usage "\n\n"
  28 //usage:       "Concatenate FILEs and print them to stdout"
  29 //usage:
  30 //usage:#define cat_example_usage
  31 //usage:       "$ cat /proc/uptime\n"
  32 //usage:       "110716.72 17.67"
  33
  34 #include "libbb.h"
  35
  36 /* This is a NOFORK applet. Be very careful! */
  37
  38
  39 int bb_cat(char **argv)
  40 {
  41         int fd;
  42         int retval = EXIT_SUCCESS;
  43
  44         if (!*argv)
  45                 argv = (char**) &bb_argv_dash;
  46
  47         do {
  48                 fd = open_or_warn_stdin(*argv);
  49                 if (fd >= 0) {
  50                         /* This is not a xfunc - never exits */
  51                         off_t r = bb_copyfd_eof(fd, STDOUT_FILENO);
  52                         if (fd != STDIN_FILENO)
  53                                 close(fd);
  54                         if (r >= 0)
  55                                 continue;
  56                 }
  57                 retval = EXIT_FAILURE;
  58         } while (*++argv);
  59
  60         return retval;
  61 }
  62
  63 int cat_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
  64 int cat_main(int argc UNUSED_PARAM, char **argv)
  65 {
  66         getopt32(argv, "u");
  67         argv += optind;
  68         return bb_cat(argv);
  69 }