-
Colin Walters authoredColin Walters authored
glnx-dirfd.c 5.54 KiB
/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*-
*
* Copyright (C) 2014,2015 Colin Walters <walters@verbum.org>.
*
* 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., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "config.h"
#include <string.h>
#include <glnx-dirfd.h>
#include <glnx-errors.h>
#include <glnx-local-alloc.h>
/**
* glnx_opendirat_with_errno:
* @dfd: File descriptor for origin directory
* @name: Pathname, relative to @dfd
* @follow: Whether or not to follow symbolic links
*
* Use openat() to open a directory, using a standard set of flags.
* This function sets errno.
*/
int
glnx_opendirat_with_errno (int dfd,
const char *path,
gboolean follow)
{
int flags = O_RDONLY | O_NONBLOCK | O_DIRECTORY | O_CLOEXEC | O_NOCTTY;
if (!follow)
flags |= O_NOFOLLOW;
return openat (dfd, path, flags);
}
/**
* glnx_opendirat:
* @dfd: File descriptor for origin directory
* @path: Pathname, relative to @dfd
* @follow: Whether or not to follow symbolic links
* @error: Error
*
* Use openat() to open a directory, using a standard set of flags.
*/
gboolean
glnx_opendirat (int dfd,
const char *path,
gboolean follow,
int *out_fd,
GError **error)
{
int ret = glnx_opendirat_with_errno (dfd, path, follow);
if (ret == -1)
{
glnx_set_prefix_error_from_errno (error, "%s", "openat");
return FALSE;
}
*out_fd = ret;
return TRUE;
}
struct GLnxRealDirfdIterator
{
gboolean initialized;
int fd;
DIR *d;
};
typedef struct GLnxRealDirfdIterator GLnxRealDirfdIterator;
/**
* glnx_dirfd_iterator_init_at:
* @dfd: File descriptor, may be AT_FDCWD or -1
* @path: Path, may be relative to @df
* @follow: If %TRUE and the last component of @path is a symlink, follow it
* @out_dfd_iter: (out caller-allocates): A directory iterator, will be initialized
* @error: Error
*
* Initialize @out_dfd_iter from @dfd and @path.
*/
gboolean
glnx_dirfd_iterator_init_at (int dfd,
const char *path,
gboolean follow,
GLnxDirFdIterator *out_dfd_iter,
GError **error)
{
gboolean ret = FALSE;
glnx_fd_close int fd = -1;
if (!glnx_opendirat (dfd, path, follow, &fd, error))
goto out;
if (!glnx_dirfd_iterator_init_take_fd (fd, dfd_iter, error))
goto out;
fd = -1; /* Transfer ownership */
ret = TRUE;
out:
return ret;
}
/**
* glnx_dirfd_iterator_init_take_fd:
* @dfd: File descriptor - ownership is taken
* @dfd_iter: A directory iterator
* @error: Error
*
* Steal ownership of @dfd, using it to initialize @dfd_iter for
* iteration.
*/
gboolean
glnx_dirfd_iterator_init_take_fd (int dfd,
GLnxDirFdIterator *dfd_iter,
GError **error)
{
gboolean ret = FALSE;
GLnxRealDirfdIterator *real_dfd_iter = (GLnxRealDirfdIterator*) dfd_iter;
DIR *d = NULL;
d = fdopendir (dfd);
if (!d)
{
glnx_set_prefix_error_from_errno (error, "%s", "fdopendir");
goto out;
}
real_dfd_iter->fd = dfd;
real_dfd_iter->d = d;
ret = TRUE;
out:
return ret;
}
/**
* glnx_dirfd_iterator_next_dent:
* @dfd_iter: A directory iterator
* @out_dent: (out) (transfer none): Pointer to dirent; do not free
* @cancellable: Cancellable
* @error: Error
*
* Read the next value from @dfd_iter, causing @out_dent to be
* updated. If end of stream is reached, @out_dent will be set
* to %NULL, and %TRUE will be returned.
*/
gboolean
glnx_dirfd_iterator_next_dent (GLnxDirFdIterator *dfd_iter,
struct dirent **out_dent,
GCancellable *cancellable,
GError **error)
{
gboolean ret = FALSE;
GLnxRealDirfdIterator *real_dfd_iter = (GLnxRealDirfdIterator*) dfd_iter;
if (g_cancellable_set_error_if_cancelled (cancellable, error))
goto out;
do
{
errno = 0;
*out_dent = readdir (real_dfd_iter->d);
if (*out_dent == NULL && errno != 0)
{
glnx_set_prefix_error_from_errno (error, "%s", "fdopendir");
goto out;
}
} while (*out_dent &&
(strcmp ((*out_dent)->d_name, ".") == 0 ||
strcmp ((*out_dent)->d_name, "..") == 0));
ret = TRUE;
out:
return ret;
}
/**
* glnx_dirfd_iterator_clear:
* @dfd_iter: Iterator, will be de-initialized
*
* Unset @dfd_iter, freeing any resources. If @dfd_iter is not
* initialized, do nothing.
*/
void
glnx_dirfd_iterator_clear (GLnxDirFdIterator *dfd_iter)
{
GLnxRealDirfdIterator *real_dfd_iter = (GLnxRealDirIterator*) dfd_iter;
/* fd is owned by dfd_iter */
(void) closedir (real_dfd_iter->d);
}