ubuntu-buildroot/output/build/host-m4-1.4.19/lib/dup.c

93 lines
1.9 KiB
C

/* Duplicate an open file descriptor.
Copyright (C) 2011-2021 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 <https://www.gnu.org/licenses/>. */
#include <config.h>
/* Specification. */
#include <unistd.h>
#include <errno.h>
#if HAVE_MSVC_INVALID_PARAMETER_HANDLER
# include "msvc-inval.h"
#endif
#undef dup
#if defined _WIN32 && !defined __CYGWIN__
# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
static int
dup_nothrow (int fd)
{
int result;
TRY_MSVC_INVAL
{
result = _dup (fd);
}
CATCH_MSVC_INVAL
{
result = -1;
errno = EBADF;
}
DONE_MSVC_INVAL;
return result;
}
# else
# define dup_nothrow _dup
# endif
#elif defined __KLIBC__
# include <fcntl.h>
# include <sys/stat.h>
# include <InnoTekLIBC/backend.h>
static int
dup_nothrow (int fd)
{
int dupfd;
struct stat sbuf;
dupfd = dup (fd);
if (dupfd == -1 && errno == ENOTSUP \
&& !fstat (fd, &sbuf) && S_ISDIR (sbuf.st_mode))
{
char path[_MAX_PATH];
/* Get a path from fd */
if (!__libc_Back_ioFHToPath (fd, path, sizeof (path)))
dupfd = open (path, O_RDONLY);
}
return dupfd;
}
#else
# define dup_nothrow dup
#endif
int
rpl_dup (int fd)
{
int result = dup_nothrow (fd);
#if REPLACE_FCHDIR
if (result >= 0)
result = _gl_register_dup (fd, result);
#endif
return result;
}