src/tee.c

   1 /* tee - read from standard input and write to standard output and files.
   2    Copyright (C) 85,1990-2006 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 "stdio--.h"
  27
  28 /* The official name of this program (e.g., no `g' prefix).  */
  29 #define PROGRAM_NAME "tee"
  30
  31 #define AUTHORS "Mike Parker", "Richard M. Stallman", "David MacKenzie"
  32
  33 static bool tee_files (int nfiles, const char **files);
  34
  35 /* If true, append to output files rather than truncating them. */
  36 static bool append;
  37
  38 /* If true, ignore interrupts. */
  39 static bool ignore_interrupts;
  40
  41 /* The name that this program was run with. */
  42 char *program_name;
  43
  44 static struct option const long_options[] =
  45 {
  46   {"append", no_argument, NULL, 'a'},
  47   {"ignore-interrupts", no_argument, NULL, 'i'},
  48   {GETOPT_HELP_OPTION_DECL},
  49   {GETOPT_VERSION_OPTION_DECL},
  50   {NULL, 0, NULL, 0}
  51 };
  52
  53 void
  54 usage (int status)
  55 {
  56   if (status != EXIT_SUCCESS)
  57     fprintf (stderr, _("Try `%s --help' for more information.\n"),
  58              program_name);
  59   else
  60     {
  61       printf (_("Usage: %s [OPTION]... [FILE]...\n"), program_name);
  62       fputs (_("\
  63 Copy standard input to each FILE, and also to standard output.\n\
  64 \n\
  65   -a, --append              append to the given FILEs, do not overwrite\n\
  66   -i, --ignore-interrupts   ignore interrupt signals\n\
  67 "), stdout);
  68       fputs (HELP_OPTION_DESCRIPTION, stdout);
  69       fputs (VERSION_OPTION_DESCRIPTION, stdout);
  70       fputs (_("\
  71 \n\
  72 If a FILE is -, copy again to standard output.\n\
  73 "), stdout);
  74       emit_bug_reporting_address ();
  75     }
  76   exit (status);
  77 }
  78
  79 int
  80 main (int argc, char **argv)
  81 {
  82   bool ok;
  83   int optc;
  84
  85   initialize_main (&argc, &argv);
  86   program_name = argv[0];
  87   setlocale (LC_ALL, "");
  88   bindtextdomain (PACKAGE, LOCALEDIR);
  89   textdomain (PACKAGE);
  90
  91   atexit (close_stdout);
  92
  93   append = false;
  94   ignore_interrupts = false;
  95
  96   while ((optc = getopt_long (argc, argv, "ai", long_options, NULL)) != -1)
  97     {
  98       switch (optc)
  99         {
 100         case 'a':
 101           append = true;
 102           break;
 103
 104         case 'i':
 105           ignore_interrupts = true;
 106           break;
 107
 108         case_GETOPT_HELP_CHAR;
 109
 110         case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
 111
 112         default:
 113           usage (EXIT_FAILURE);
 114         }
 115     }
 116
 117   if (ignore_interrupts)
 118     signal (SIGINT, SIG_IGN);
 119
 120   /* Do *not* warn if tee is given no file arguments.
 121      POSIX requires that it work when given no arguments.  */
 122
 123   ok = tee_files (argc - optind, (const char **) &argv[optind]);
 124   if (close (STDIN_FILENO) != 0)
 125     error (EXIT_FAILURE, errno, _("standard input"));
 126
 127   exit (ok ? EXIT_SUCCESS : EXIT_FAILURE);
 128 }
 129
 130 /* Copy the standard input into each of the NFILES files in FILES
 131    and into the standard output.
 132    Return true if successful.  */
 133
 134 static bool
 135 tee_files (int nfiles, const char **files)
 136 {
 137   FILE **descriptors;
 138   char buffer[BUFSIZ];
 139   ssize_t bytes_read;
 140   int i;
 141   bool ok = true;
 142   char const *mode_string =
 143     (O_BINARY
 144      ? (append ? "ab" : "wb")
 145      : (append ? "a" : "w"));
 146
 147   descriptors = xnmalloc (nfiles + 1, sizeof *descriptors);
 148
 149   /* Move all the names `up' one in the argv array to make room for
 150      the entry for standard output.  This writes into argv[argc].  */
 151   for (i = nfiles; i >= 1; i--)
 152     files[i] = files[i - 1];
 153
 154   if (O_BINARY && ! isatty (STDIN_FILENO))
 155     freopen (NULL, "rb", stdin);
 156   if (O_BINARY && ! isatty (STDOUT_FILENO))
 157     freopen (NULL, "wb", stdout);
 158
 159   /* In the array of NFILES + 1 descriptors, make
 160      the first one correspond to standard output.   */
 161   descriptors[0] = stdout;
 162   files[0] = _("standard output");
 163   setvbuf (stdout, NULL, _IONBF, 0);
 164
 165   for (i = 1; i <= nfiles; i++)
 166     {
 167       descriptors[i] = (STREQ (files[i], "-")
 168                         ? stdout
 169                         : fopen (files[i], mode_string));
 170       if (descriptors[i] == NULL)
 171         {
 172           error (0, errno, "%s", files[i]);
 173           ok = false;
 174         }
 175       else
 176         setvbuf (descriptors[i], NULL, _IONBF, 0);
 177     }
 178
 179   while (1)
 180     {
 181       bytes_read = read (0, buffer, sizeof buffer);
 182 #ifdef EINTR
 183       if (bytes_read < 0 && errno == EINTR)
 184         continue;
 185 #endif
 186       if (bytes_read <= 0)
 187         break;
 188
 189       /* Write to all NFILES + 1 descriptors.
 190          Standard output is the first one.  */
 191       for (i = 0; i <= nfiles; i++)
 192         if (descriptors[i]
 193             && fwrite (buffer, 1, bytes_read, descriptors[i]) != bytes_read)
 194           {
 195             error (0, errno, "%s", files[i]);
 196             descriptors[i] = NULL;
 197             ok = false;
 198           }
 199     }
 200
 201   if (bytes_read == -1)
 202     {
 203       error (0, errno, _("read error"));
 204       ok = false;
 205     }
 206
 207   /* Close the files, but not standard output.  */
 208   for (i = 1; i <= nfiles; i++)
 209     if (!STREQ (files[i], "-")
 210         && descriptors[i] && fclose (descriptors[i]) != 0)
 211       {
 212         error (0, errno, "%s", files[i]);
 213         ok = false;
 214       }
 215
 216   free (descriptors);
 217
 218   return ok;
 219 }