src/tee.c

   1 /* tee - read from standard input and write to standard output and files.
   2    Copyright (C) 1985, 1990-2006, 2008-2011 Free Software Foundation, Inc.
   3
   4    This program is free software: you can redistribute it and/or modify
   5    it under the terms of the GNU General Public License as published by
   6    the Free Software Foundation, either version 3 of the License, or
   7    (at your option) any later version.
   8
   9    This program is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12    GNU General Public License for more details.
  13
  14    You should have received a copy of the GNU General Public License
  15    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  16
  17 /* Mike Parker, Richard M. Stallman, and David MacKenzie */
  18
  19 #include <config.h>
  20 #include <sys/types.h>
  21 #include <signal.h>
  22 #include <getopt.h>
  23
  24 #include "system.h"
  25 #include "error.h"
  26 #include "fadvise.h"
  27 #include "stdio--.h"
  28 #include "xfreopen.h"
  29
  30 /* The official name of this program (e.g., no `g' prefix).  */
  31 #define PROGRAM_NAME "tee"
  32
  33 #define AUTHORS \
  34   proper_name ("Mike Parker"), \
  35   proper_name ("Richard M. Stallman"), \
  36   proper_name ("David MacKenzie")
  37
  38 static bool tee_files (int nfiles, const char **files);
  39
  40 /* If true, append to output files rather than truncating them. */
  41 static bool append;
  42
  43 /* If true, ignore interrupts. */
  44 static bool ignore_interrupts;
  45
  46 static struct option const long_options[] =
  47 {
  48   {"append", no_argument, NULL, 'a'},
  49   {"ignore-interrupts", no_argument, NULL, 'i'},
  50   {GETOPT_HELP_OPTION_DECL},
  51   {GETOPT_VERSION_OPTION_DECL},
  52   {NULL, 0, NULL, 0}
  53 };
  54
  55 void
  56 usage (int status)
  57 {
  58   if (status != EXIT_SUCCESS)
  59     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  60              program_name);
  61   else
  62     {
  63       printf (_("Usage: %s [OPTION]... [FILE]...\n"), program_name);
  64       fputs (_("\
  65 Copy standard input to each FILE, and also to standard output.\n\
  66 \n\
  67   -a, --append              append to the given FILEs, do not overwrite\n\
  68   -i, --ignore-interrupts   ignore interrupt signals\n\
  69 "), stdout);
  70       fputs (HELP_OPTION_DESCRIPTION, stdout);
  71       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  72       fputs (_("\
  73 \n\
  74 If a FILE is -, copy again to standard output.\n\
  75 "), stdout);
  76       emit_ancillary_info ();
  77     }
  78   exit (status);
  79 }
  80
  81 int
  82 main (int argc, char **argv)
  83 {
  84   bool ok;
  85   int optc;
  86
  87   initialize_main (&argc, &argv);
  88   set_program_name (argv[0]);
  89   setlocale (LC_ALL, "");
  90   bindtextdomain (PACKAGE, LOCALEDIR);
  91   textdomain (PACKAGE);
  92
  93   atexit (close_stdout);
  94
  95   append = false;
  96   ignore_interrupts = false;
  97
  98   while ((optc = getopt_long (argc, argv, "ai", long_options, NULL)) != -1)
  99     {
 100       switch (optc)
 101         {
 102         case 'a':
 103           append = true;
 104           break;
 105
 106         case 'i':
 107           ignore_interrupts = true;
 108           break;
 109
 110         case_GETOPT_HELP_CHAR;
 111
 112         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 113
 114         default:
 115           usage (EXIT_FAILURE);
 116         }
 117     }
 118
 119   if (ignore_interrupts)
 120     signal (SIGINT, SIG_IGN);
 121
 122   /* Do *not* warn if tee is given no file arguments.
 123      POSIX requires that it work when given no arguments.  */
 124
 125   ok = tee_files (argc - optind, (const char **) &argv[optind]);
 126   if (close (STDIN_FILENO) != 0)
 127     error (EXIT_FAILURE, errno, _("standard input"));
 128
 129   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 130 }
 131
 132 /* Copy the standard input into each of the NFILES files in FILES
 133    and into the standard output.
 134    Return true if successful.  */
 135
 136 static bool
 137 tee_files (int nfiles, const char **files)
 138 {
 139   FILE **descriptors;
 140   char buffer[BUFSIZ];
 141   ssize_t bytes_read;
 142   int i;
 143   bool ok = true;
 144   char const *mode_string =
 145     (O_BINARY
 146      ? (append ? "ab" : "wb")
 147      : (append ? "a" : "w"));
 148
 149   descriptors = xnmalloc (nfiles + 1, sizeof *descriptors);
 150
 151   /* Move all the names `up' one in the argv array to make room for
 152      the entry for standard output.  This writes into argv[argc].  */
 153   for (i = nfiles; i >= 1; i--)
 154     files[i] = files[i - 1];
 155
 156   if (O_BINARY && ! isatty (STDIN_FILENO))
 157     xfreopen (NULL, "rb", stdin);
 158   if (O_BINARY && ! isatty (STDOUT_FILENO))
 159     xfreopen (NULL, "wb", stdout);
 160
 161   fadvise (stdin, FADVISE_SEQUENTIAL);
 162
 163   /* In the array of NFILES + 1 descriptors, make
 164      the first one correspond to standard output.   */
 165   descriptors[0] = stdout;
 166   files[0] = _("standard output");
 167   setvbuf (stdout, NULL, _IONBF, 0);
 168
 169   for (i = 1; i <= nfiles; i++)
 170     {
 171       descriptors[i] = (STREQ (files[i], "-")
 172                         ? stdout
 173                         : fopen (files[i], mode_string));
 174       if (descriptors[i] == NULL)
 175         {
 176           error (0, errno, "%s", files[i]);
 177           ok = false;
 178         }
 179       else
 180         setvbuf (descriptors[i], NULL, _IONBF, 0);
 181     }
 182
 183   while (1)
 184     {
 185       bytes_read = read (0, buffer, sizeof buffer);
 186       if (bytes_read < 0 && errno == EINTR)
 187         continue;
 188       if (bytes_read <= 0)
 189         break;
 190
 191       /* Write to all NFILES + 1 descriptors.
 192          Standard output is the first one.  */
 193       for (i = 0; i <= nfiles; i++)
 194         if (descriptors[i]
 195             && fwrite (buffer, bytes_read, 1, descriptors[i]) != 1)
 196           {
 197             error (0, errno, "%s", files[i]);
 198             descriptors[i] = NULL;
 199             ok = false;
 200           }
 201     }
 202
 203   if (bytes_read == -1)
 204     {
 205       error (0, errno, _("read error"));
 206       ok = false;
 207     }
 208
 209   /* Close the files, but not standard output.  */
 210   for (i = 1; i <= nfiles; i++)
 211     if (!STREQ (files[i], "-")
 212         && descriptors[i] && fclose (descriptors[i]) != 0)
 213       {
 214         error (0, errno, "%s", files[i]);
 215         ok = false;
 216       }
 217
 218   free (descriptors);
 219
 220   return ok;
 221 }