lib/sh/zmapfd.c

   1 /* zmapfd - read contents of file descriptor into a newly-allocated buffer */
   2
   3 /* Copyright (C) 2006 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 "bashansi.h"
  32 #include "command.h"
  33 #include "general.h"
  34
  35 #if !defined (errno)
  36 extern int errno;
  37 #endif
  38
  39 extern ssize_t zread __P((int, char *, size_t));
  40
  41 /* Dump contents of file descriptor FD to *OSTR.  FN is the filename for
  42    error messages (not used right now). */
  43 int
  44 zmapfd (fd, ostr, fn)
  45      int fd;
  46      char **ostr;
  47      char *fn;
  48 {
  49   ssize_t nr;
  50   int rval;
  51   char lbuf[128];
  52   char *result;
  53   int rsize, rind;
  54
  55   rval = 0;
  56   result = (char *)xmalloc (rsize = 64);
  57   rind = 0;
  58
  59   while (1)
  60     {
  61       nr = zread (fd, lbuf, sizeof (lbuf));
  62       if (nr == 0)
  63         {
  64           rval = rind;
  65           break;
  66         }
  67       else if (nr < 0)
  68         {
  69           free (result);
  70           if (ostr)
  71             *ostr = (char *)NULL;
  72           return -1;
  73         }
  74
  75       RESIZE_MALLOCED_BUFFER (result, rind, nr, rsize, 128);
  76       memcpy (result+rind, lbuf, nr);
  77       rind += nr;
  78     }
  79
  80   RESIZE_MALLOCED_BUFFER (result, rind, 1, rsize, 128);
  81   result[rind] = '\0';
  82
  83   if (ostr)
  84     *ostr = result;
  85   else
  86     free (result);
  87
  88   return rval;
  89 }