"Fossies" - the Fresh Open Source Software Archive

Member "gnuastro-0.9/bootstrapped/lib/fd-safer.c" (17 Apr 2019, 1539 Bytes) of package /linux/privat/gnuastro-0.9.tar.lz:


As a special service "Fossies" has tried to format the requested source page into HTML format using (guessed) C and C++ source code syntax highlighting (style: standard) with prefixed line numbers and code folding option. Alternatively you can here view or download the uninterpreted source code file. For more information about "fd-safer.c" see the Fossies "Dox" file reference documentation.

    1 /* Return a safer copy of a file descriptor.
    2 
    3    Copyright (C) 2005-2006, 2009-2019 Free Software Foundation, Inc.
    4 
    5    This program is free software: you can redistribute it and/or modify
    6    it under the terms of the GNU General Public License as published by
    7    the Free Software Foundation; either version 3 of the License, or
    8    (at your option) any later version.
    9 
   10    This program is distributed in the hope that it will be useful,
   11    but WITHOUT ANY WARRANTY; without even the implied warranty of
   12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   13    GNU General Public License for more details.
   14 
   15    You should have received a copy of the GNU General Public License
   16    along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
   17 
   18 /* Written by Paul Eggert.  */
   19 
   20 #include <config.h>
   21 
   22 #include "unistd-safer.h"
   23 
   24 #include <errno.h>
   25 #include <unistd.h>
   26 
   27 /* Return FD, unless FD would be a copy of standard input, output, or
   28    error; in that case, return a duplicate of FD, closing FD.  On
   29    failure to duplicate, close FD, set errno, and return -1.  Preserve
   30    errno if FD is negative, so that the caller can always inspect
   31    errno when the returned value is negative.
   32 
   33    This function is usefully wrapped around functions that return file
   34    descriptors, e.g., fd_safer (open ("file", O_RDONLY)).  */
   35 
   36 int
   37 fd_safer (int fd)
   38 {
   39   if (STDIN_FILENO <= fd && fd <= STDERR_FILENO)
   40     {
   41       int f = dup_safer (fd);
   42       int e = errno;
   43       close (fd);
   44       errno = e;
   45       fd = f;
   46     }
   47 
   48   return fd;
   49 }