dir: New DIR* facade

1 files changed, 200 insertions, 0 deletions

diff --git a/dir.c b/dir.c
new file mode 100644
index 0000000..23aa62d
--- /dev/null
+++ b/dir.c
@@ -0,0 +1,200 @@
+/****************************************************************************
+ * bfs                                                                      *
+ * Copyright (C) 2021 Tavian Barnes <tavianator@tavianator.com>             *
+ *                                                                          *
+ * Permission to use, copy, modify, and/or distribute this software for any *
+ * purpose with or without fee is hereby granted.                           *
+ *                                                                          *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
+ ****************************************************************************/
+
+#include "dir.h"
+#include "util.h"
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdbool.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+enum bfs_type bfs_mode_to_type(mode_t mode) {
+	switch (mode & S_IFMT) {
+#ifdef S_IFBLK
+	case S_IFBLK:
+		return BFS_BLK;
+#endif
+#ifdef S_IFCHR
+	case S_IFCHR:
+		return BFS_CHR;
+#endif
+#ifdef S_IFDIR
+	case S_IFDIR:
+		return BFS_DIR;
+#endif
+#ifdef S_IFDOOR
+	case S_IFDOOR:
+		return BFS_DOOR;
+#endif
+#ifdef S_IFIFO
+	case S_IFIFO:
+		return BFS_FIFO;
+#endif
+#ifdef S_IFLNK
+	case S_IFLNK:
+		return BFS_LNK;
+#endif
+#ifdef S_IFPORT
+	case S_IFPORT:
+		return BFS_PORT;
+#endif
+#ifdef S_IFREG
+	case S_IFREG:
+		return BFS_REG;
+#endif
+#ifdef S_IFSOCK
+	case S_IFSOCK:
+		return BFS_SOCK;
+#endif
+#ifdef S_IFWHT
+	case S_IFWHT:
+		return BFS_WHT;
+#endif
+
+	default:
+		return BFS_UNKNOWN;
+	}
+}
+
+struct bfs_dir {
+	DIR *dir;
+	struct dirent *ent;
+};
+
+struct bfs_dir *bfs_opendir(int at_fd, const char *at_path) {
+	struct bfs_dir *dir = malloc(sizeof(*dir));
+	if (!dir) {
+		return NULL;
+	}
+
+	int fd;
+	if (at_path) {
+		fd = openat(at_fd, at_path, O_RDONLY | O_CLOEXEC | O_DIRECTORY);
+	} else if (at_fd >= 0) {
+		fd = at_fd;
+	} else {
+		free(dir);
+		errno = EBADF;
+		return NULL;
+	}
+
+	if (fd < 0) {
+		free(dir);
+		return NULL;
+	}
+
+	dir->dir = fdopendir(fd);
+	if (!dir->dir) {
+		int error = errno;
+		close(fd);
+		free(dir);
+		errno = error;
+		return NULL;
+	}
+
+	dir->ent = NULL;
+
+	return dir;
+}
+
+int bfs_dirfd(const struct bfs_dir *dir) {
+	return dirfd(dir->dir);
+}
+
+static enum bfs_type dirent_type(const struct dirent *de) {
+#if defined(_DIRENT_HAVE_D_TYPE) || defined(DT_UNKNOWN)
+	switch (de->d_type) {
+#ifdef DT_BLK
+	case DT_BLK:
+		return BFS_BLK;
+#endif
+#ifdef DT_CHR
+	case DT_CHR:
+		return BFS_CHR;
+#endif
+#ifdef DT_DIR
+	case DT_DIR:
+		return BFS_DIR;
+#endif
+#ifdef DT_DOOR
+	case DT_DOOR:
+		return BFS_DOOR;
+#endif
+#ifdef DT_FIFO
+	case DT_FIFO:
+		return BFS_FIFO;
+#endif
+#ifdef DT_LNK
+	case DT_LNK:
+		return BFS_LNK;
+#endif
+#ifdef DT_PORT
+	case DT_PORT:
+		return BFS_PORT;
+#endif
+#ifdef DT_REG
+	case DT_REG:
+		return BFS_REG;
+#endif
+#ifdef DT_SOCK
+	case DT_SOCK:
+		return BFS_SOCK;
+#endif
+#ifdef DT_WHT
+	case DT_WHT:
+		return BFS_WHT;
+#endif
+	}
+#endif
+
+	return BFS_UNKNOWN;
+}
+
+int bfs_readdir(struct bfs_dir *dir, struct bfs_dirent *dirent) {
+	while (true) {
+		errno = 0;
+		dir->ent = readdir(dir->dir);
+		if (dir->ent) {
+			const char *name = dir->ent->d_name;
+			if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' && name[2] == '\0'))) {
+				continue;
+			}
+			if (dirent) {
+				dirent->type = dirent_type(dir->ent);
+				dirent->name = name;
+			}
+			return 1;
+		} else if (errno != 0) {
+			return -1;
+		} else {
+			return 0;
+		}
+	}
+}
+
+int bfs_closedir(struct bfs_dir *dir) {
+	int ret = closedir(dir->dir);
+	free(dir);
+	return ret;
+}
+
+int bfs_freedir(struct bfs_dir *dir) {
+	int ret = dup_cloexec(dirfd(dir->dir));
+	bfs_closedir(dir);
+	return ret;
+}