lib/sh/zmapfd.c

   1 /* zmapfd - read contents of file descriptor into a newly-allocated buffer */
   2
   3 /* Copyright (C) 2006-2020 Free Software Foundation, Inc.
   4
   5    This file is part of GNU Bush, the Bourne Again SHell.
   6
   7    Bush 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    Bush 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 Bush.  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 "bushansi.h"
  32 #include "lxrgmr/command.h"
  33 #include "general.h"
  34
  35 #if !defined (errno)
  36 extern int errno;
  37 #endif
  38
  39 #ifndef ZBUFSIZ
  40 #  define ZBUFSIZ 4096
  41 #endif
  42
  43 extern ssize_t zread PARAMS((int, char *, size_t));
  44
  45 /* Dump contents of file descriptor FD to *OSTR.  FN is the filename for
  46    error messages (not used right now). */
  47 int
  48 zmapfd (fd, ostr, fn)
  49      int fd;
  50      char **ostr;
  51      char *fn;
  52 {
  53   ssize_t nr;
  54   int rval;
  55   char lbuf[ZBUFSIZ];
  56   char *result;
  57   int rsize, rind;
  58
  59   rval = 0;
  60   result = (char *)xmalloc (rsize = ZBUFSIZ);
  61   rind = 0;
  62
  63   while (1)
  64     {
  65       nr = zread (fd, lbuf, sizeof (lbuf));
  66       if (nr == 0)
  67         {
  68           rval = rind;
  69           break;
  70         }
  71       else if (nr < 0)
  72         {
  73           free (result);
  74           if (ostr)
  75             *ostr = (char *)NULL;
  76           return -1;
  77         }
  78
  79       RESIZE_MALLOCED_BUFFER (result, rind, nr, rsize, ZBUFSIZ);
  80       memcpy (result+rind, lbuf, nr);
  81       rind += nr;
  82     }
  83
  84   RESIZE_MALLOCED_BUFFER (result, rind, 1, rsize, 128);
  85   result[rind] = '\0';
  86
  87   if (ostr)
  88     *ostr = result;
  89   else
  90     free (result);
  91
  92   return rval;
  93 }