/* -*- 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); }