examples/loadables/tee.c

   1 /* tee - duplicate standard input */
   2
   3 /* See Makefile for compilation details. */
   4
   5 /*
   6    Copyright (C) 1999-2009 Free Software Foundation, Inc.
   7
   8    This file is part of GNU Bash.
   9    Bash is free software: you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation, either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    Bash is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  21 */
  22
  23 #include "config.h"
  24
  25 #include "bashtypes.h"
  26 #include "posixstat.h"
  27 #include "filecntl.h"
  28
  29 #include <signal.h>
  30
  31 #if defined (HAVE_UNISTD_H)
  32 #  include <unistd.h>
  33 #endif
  34
  35 #include "bashansi.h"
  36
  37 #include <stdio.h>
  38 #include <errno.h>
  39
  40 #include "builtins.h"
  41 #include "shell.h"
  42 #include "bashgetopt.h"
  43 #include "common.h"
  44
  45 #if !defined (errno)
  46 extern int errno;
  47 #endif
  48
  49 typedef struct flist {
  50   struct flist *next;
  51   int fd;
  52   char *fname;
  53 } FLIST;
  54
  55 static FLIST *tee_flist;
  56
  57 #define TEE_BUFSIZE     8192
  58
  59 extern int interrupt_immediately;
  60
  61 extern char *strerror ();
  62
  63 tee_builtin (list)
  64      WORD_LIST *list;
  65 {
  66   int opt, append, nointr, rval, fd, fflags;
  67   int n, nr, nw;
  68   FLIST *fl;
  69   char *buf, *bp;
  70
  71   char *t;
  72
  73   reset_internal_getopt ();
  74   append = nointr = 0;
  75   tee_flist = (FLIST *)NULL;
  76   while ((opt = internal_getopt (list, "ai")) != -1)
  77     {
  78       switch (opt)
  79         {
  80         case 'a':
  81           append = 1;
  82           break;
  83         case 'i':
  84           nointr = 1;
  85           break;
  86         default:
  87           builtin_usage ();
  88           return (EX_USAGE);
  89         }
  90     }
  91   list = loptend;
  92
  93   if (nointr == 0)
  94     interrupt_immediately++;
  95
  96   buf = xmalloc (TEE_BUFSIZE);
  97
  98   /* Initialize output file list. */
  99   fl = tee_flist = (FLIST *)xmalloc (sizeof(FLIST));
 100   tee_flist->fd = 1;
 101   tee_flist->fname = "stdout";
 102   tee_flist->next = (FLIST *)NULL;
 103
 104   /* Add file arguments to list of output files. */
 105   fflags = append ? O_WRONLY|O_CREAT|O_APPEND : O_WRONLY|O_CREAT|O_TRUNC;
 106   for (rval = EXECUTION_SUCCESS; list; list = list->next)
 107     {
 108       fd = open (list->word->word, fflags, 0666);
 109       if (fd < 0)
 110         {
 111           builtin_error ("%s: cannot open: %s", list->word->word, strerror (errno));
 112           rval = EXECUTION_FAILURE;
 113         }
 114       else
 115         {
 116           fl->next = (FLIST *)xmalloc (sizeof(FLIST));
 117           fl->next->fd = fd;
 118           fl->next->fname = list->word->word;
 119           fl = fl->next;
 120           fl->next = (FLIST *)NULL;
 121         }
 122     }
 123
 124   while ((nr = read(0, buf, TEE_BUFSIZE)) > 0)
 125     for (fl = tee_flist; fl; fl = fl->next)
 126       {
 127         n = nr;
 128         bp = buf;
 129         do
 130           {
 131             if ((nw = write (fl->fd, bp, n)) == -1)
 132               {
 133                 builtin_error ("%s: write error: %s", fl->fname, strerror (errno));
 134                 rval = EXECUTION_FAILURE;
 135                 break;
 136               }
 137             bp += nw;
 138           }
 139         while (n -= nw);
 140       }
 141   if (nr < 0)
 142     builtin_error ("read error: %s", strerror (errno));
 143
 144   /* Deallocate resources -- this is a builtin command. */
 145   tee_flist = tee_flist->next;          /* skip bogus close of stdout */
 146   while (tee_flist)
 147     {
 148       fl = tee_flist;
 149       if (close (fl->fd) < 0)
 150         {
 151           builtin_error ("%s: close_error: %s", fl->fname, strerror (errno));
 152           rval = EXECUTION_FAILURE;
 153         }
 154       tee_flist = tee_flist->next;
 155       free (fl);
 156     }
 157
 158   return (rval);
 159 }
 160
 161 char *tee_doc[] = {
 162         "Duplicate standard output.",
 163         "",
 164         "Copy standard input to standard output, making a copy in each",
 165         "filename argument.  If the `-a' option is gived, the specified",
 166         "files are appended to, otherwise they are overwritten.  If the",
 167         "`-i' option is supplied, tee ignores interrupts.",
 168         (char *)NULL
 169 };
 170
 171 struct builtin tee_struct = {
 172         "tee",                  /* builtin name */
 173         tee_builtin,            /* function implementing the builtin */
 174         BUILTIN_ENABLED,        /* initial flags for builtin */
 175         tee_doc,                /* array of long documentation strings. */
 176         "tee [-ai] [file ...]", /* usage synopsis; becomes short_doc */
 177         0                       /* reserved for internal use */
 178 };