kc3-lang/gnulib/lib/cloexec.c

• Show log

  Commit

• Hash : d60f3b0c
  Author :
  Date : 2011-01-01T20:17:23
  

  maint: update almost all copyright ranges to include 2011
  
  Run the new "make update-copyright" rule.
  

Download

• lib/cloexec.c

• /* closexec.c - set or clear the close-on-exec descriptor flag
  
     Copyright (C) 1991, 2004-2006, 2009-2011 Free Software Foundation, Inc.
  
     This program is free software: you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 3 of the License, or
     (at your option) any later version.
  
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
  
     You should have received a copy of the GNU General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  
     The code is taken from glibc/manual/llio.texi  */
  
  #include <config.h>
  
  #include "cloexec.h"
  
  #include <errno.h>
  #include <fcntl.h>
  #include <unistd.h>
  
  /* Set the `FD_CLOEXEC' flag of DESC if VALUE is true,
     or clear the flag if VALUE is false.
     Return 0 on success, or -1 on error with `errno' set.
  
     Note that on MingW, this function does NOT protect DESC from being
     inherited into spawned children.  Instead, either use dup_cloexec
     followed by closing the original DESC, or use interfaces such as
     open or pipe2 that accept flags like O_CLOEXEC to create DESC
     non-inheritable in the first place.  */
  
  int
  set_cloexec_flag (int desc, bool value)
  {
  #ifdef F_SETFD
  
    int flags = fcntl (desc, F_GETFD, 0);
  
    if (0 <= flags)
      {
        int newflags = (value ? flags | FD_CLOEXEC : flags & ~FD_CLOEXEC);
  
        if (flags == newflags
            || fcntl (desc, F_SETFD, newflags) != -1)
          return 0;
      }
  
    return -1;
  
  #else /* !F_SETFD */
  
    /* Use dup2 to reject invalid file descriptors; the cloexec flag
       will be unaffected.  */
    if (desc < 0)
      {
        errno = EBADF;
        return -1;
      }
    if (dup2 (desc, desc) < 0)
      /* errno is EBADF here.  */
      return -1;
  
    /* There is nothing we can do on this kind of platform.  Punt.  */
    return 0;
  #endif /* !F_SETFD */
  }
  
  
  /* Duplicates a file handle FD, while marking the copy to be closed
     prior to exec or spawn.  Returns -1 and sets errno if FD could not
     be duplicated.  */
  
  int
  dup_cloexec (int fd)
  {
    return fcntl (fd, F_DUPFD_CLOEXEC, 0);
  }
  

Download