Files
libguestfs/gnulib/lib/cloexec.c
Richard W.M. Jones e2c7bddf10 Update copyright dates for 2023
Run this command across the source:

  perl -pi.bak -e 's/(20[012][0-9])-20[12][012]/$1-2023/g' `git ls-files`

and remove changes to po{,-docs}/*.po{,t} (these will be regenerated
later when we run 'make dist').
2023-02-07 10:50:48 +00:00

89 lines
2.6 KiB
C

/* cloexec.c - set or clear the close-on-exec descriptor flag
Copyright (C) 1991, 2004-2006, 2009-2023 Free Software Foundation, Inc.
(NB: I modified the original GPL boilerplate here to LGPLv2+. This
is because of the weird way that gnulib uses licenses, where the
real license is covered in the modules/X file. The real license
for this file is LGPLv2+, not GPL. - RWMJ)
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2 of the License, or (at your option) any later version.
This library 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#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);
}