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emacs/lib/dirfd.c
Paul Eggert a0202fdc85 Merge from Gnulib
This incorporates:
2017-09-13 all: prefer https: URLs
This just changes http: to https: in comments,
in files copied from Gnulib.
2017-09-13 02:08:36 -07:00

99 lines
2.3 KiB
C

/* dirfd.c -- return the file descriptor associated with an open DIR*
Copyright (C) 2001, 2006, 2008-2017 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/>. */
/* Written by Jim Meyering. */
#include <config.h>
#include <dirent.h>
#include <errno.h>
#ifdef __KLIBC__
# include <stdlib.h>
# include <io.h>
static struct dirp_fd_list
{
DIR *dirp;
int fd;
struct dirp_fd_list *next;
} *dirp_fd_start = NULL;
/* Register fd associated with dirp to dirp_fd_list. */
int
_gl_register_dirp_fd (int fd, DIR *dirp)
{
struct dirp_fd_list *new_dirp_fd = malloc (sizeof *new_dirp_fd);
if (!new_dirp_fd)
return -1;
new_dirp_fd->dirp = dirp;
new_dirp_fd->fd = fd;
new_dirp_fd->next = dirp_fd_start;
dirp_fd_start = new_dirp_fd;
return 0;
}
/* Unregister fd from dirp_fd_list with closing it */
void
_gl_unregister_dirp_fd (int fd)
{
struct dirp_fd_list *dirp_fd;
struct dirp_fd_list *dirp_fd_prev;
for (dirp_fd_prev = NULL, dirp_fd = dirp_fd_start; dirp_fd;
dirp_fd_prev = dirp_fd, dirp_fd = dirp_fd->next)
{
if (dirp_fd->fd == fd)
{
if (dirp_fd_prev)
dirp_fd_prev->next = dirp_fd->next;
else /* dirp_fd == dirp_fd_start */
dirp_fd_start = dirp_fd_start->next;
close (fd);
free (dirp_fd);
break;
}
}
}
#endif
int
dirfd (DIR *dir_p)
{
int fd = DIR_TO_FD (dir_p);
if (fd == -1)
#ifndef __KLIBC__
errno = ENOTSUP;
#else
{
struct dirp_fd_list *dirp_fd;
for (dirp_fd = dirp_fd_start; dirp_fd; dirp_fd = dirp_fd->next)
if (dirp_fd->dirp == dir_p)
return dirp_fd->fd;
errno = EINVAL;
}
#endif
return fd;
}