lib/sh/zcatfd.c

   1 /* zcatfd - copy contents of file descriptor to another */
   2
   3 /* Copyright (C) 2002 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bash, the Bourne Again SHell.
   6
   7    Bash is free software: you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation, either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    Bash is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bash.  If not, see <http://www.gnu.org/licenses/>.
  19 */
  20
  21 #include <config.h>
  22
  23 #include <sys/types.h>
  24
  25 #if defined (HAVE_UNISTD_H)
  26 #  include <unistd.h>
  27 #endif
  28
  29 #include <errno.h>
  30
  31 #include <stdc.h>
  32
  33 #if !defined (errno)
  34 extern int errno;
  35 #endif
  36
  37 extern ssize_t zread __P((int, char *, size_t));
  38 extern int zwrite __P((int, char *, ssize_t));
  39
  40 /* Dump contents of file descriptor FD to OFD.  FN is the filename for
  41    error messages (not used right now). */
  42 int
  43 zcatfd (fd, ofd, fn)
  44      int fd, ofd;
  45      char *fn;
  46 {
  47   ssize_t nr;
  48   int rval;
  49   char lbuf[128];
  50
  51   rval = 0;
  52   while (1)
  53     {
  54       nr = zread (fd, lbuf, sizeof (lbuf));
  55       if (nr == 0)
  56         break;
  57       else if (nr < 0)
  58         {
  59           rval = -1;
  60           break;
  61         }
  62       else if (zwrite (ofd, lbuf, nr) < 0)
  63         {
  64           rval = -1;
  65           break;
  66         }
  67     }
  68
  69   return rval;
  70 }