1 files changed, 171 insertions, 0 deletions
diff --git a/src/dir.h b/src/dir.h
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+++ b/src/dir.h
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+// Copyright © Tavian Barnes <tavianator@tavianator.com>
+// SPDX-License-Identifier: 0BSD
+
+/**
+ * Directories and their contents.
+ */
+
+#ifndef BFS_DIR_H
+#define BFS_DIR_H
+
+#include "prelude.h"
+#include <sys/types.h>
+
+/**
+ * Whether the implementation uses the getdents() syscall directly, rather than
+ * libc's readdir().
+ */
+#if !defined(BFS_USE_GETDENTS) && (__linux__ || __FreeBSD__)
+#  define BFS_USE_GETDENTS (BFS_HAS_GETDENTS || BFS_HAS_GETDENTS64 | BFS_HAS_GETDENTS64_SYSCALL)
+#endif
+
+/**
+ * A directory.
+ */
+struct bfs_dir;
+
+/**
+ * File types.
+ */
+enum bfs_type {
+	/** An error occurred for this file. */
+	BFS_ERROR = -1,
+	/** Unknown type. */
+	BFS_UNKNOWN,
+	/** Block device. */
+	BFS_BLK,
+	/** Character device. */
+	BFS_CHR,
+	/** Directory. */
+	BFS_DIR,
+	/** Solaris door. */
+	BFS_DOOR,
+	/** Pipe. */
+	BFS_FIFO,
+	/** Symbolic link. */
+	BFS_LNK,
+	/** Solaris event port. */
+	BFS_PORT,
+	/** Regular file. */
+	BFS_REG,
+	/** Socket. */
+	BFS_SOCK,
+	/** BSD whiteout. */
+	BFS_WHT,
+};
+
+/**
+ * Convert a bfs_stat() mode to a bfs_type.
+ */
+enum bfs_type bfs_mode_to_type(mode_t mode);
+
+/**
+ * A directory entry.
+ */
+struct bfs_dirent {
+	/** The type of this file (possibly unknown). */
+	enum bfs_type type;
+	/** The name of this file. */
+	const char *name;
+};
+
+/**
+ * Allocate space for a directory.
+ *
+ * @return
+ *         An allocated, unopen directory, or NULL on failure.
+ */
+struct bfs_dir *bfs_allocdir(void);
+
+struct arena;
+
+/**
+ * Initialize an arena for directories.
+ *
+ * @param arena
+ *         The arena to initialize.
+ */
+void bfs_dir_arena(struct arena *arena);
+
+/**
+ * bfs_opendir() flags.
+ */
+enum bfs_dir_flags {
+	/** Include whiteouts in the results. */
+	BFS_DIR_WHITEOUTS = 1 << 0,
+	/** @internal Start of private flags. */
+	BFS_DIR_PRIVATE   = 1 << 1,
+};
+
+/**
+ * Open a directory.
+ *
+ * @param dir
+ *         The allocated directory.
+ * @param at_fd
+ *         The base directory for path resolution.
+ * @param at_path
+ *         The path of the directory to open, relative to at_fd.  Pass NULL to
+ *         open at_fd itself.
+ * @param flags
+ *         Flags that control which directory entries are listed.
+ * @return
+ *         0 on success, or -1 on failure.
+ */
+int bfs_opendir(struct bfs_dir *dir, int at_fd, const char *at_path, enum bfs_dir_flags flags);
+
+/**
+ * Get the file descriptor for a directory.
+ */
+int bfs_dirfd(const struct bfs_dir *dir);
+
+/**
+ * Performs any I/O necessary for the next bfs_readdir() call.
+ *
+ * @param dir
+ *         The directory to poll.
+ * @return
+ *         1 on success, 0 on EOF, or -1 on failure.
+ */
+int bfs_polldir(struct bfs_dir *dir);
+
+/**
+ * Read a directory entry.
+ *
+ * @param dir
+ *         The directory to read.
+ * @param[out] dirent
+ *         The directory entry to populate.
+ * @return
+ *         1 on success, 0 on EOF, or -1 on failure.
+ */
+int bfs_readdir(struct bfs_dir *dir, struct bfs_dirent *de);
+
+/**
+ * Close a directory.
+ *
+ * @return
+ *         0 on success, -1 on failure.
+ */
+int bfs_closedir(struct bfs_dir *dir);
+
+/**
+ * Whether the bfs_unwrapdir() function is supported.
+ */
+#ifndef BFS_USE_UNWRAPDIR
+#  define BFS_USE_UNWRAPDIR (BFS_USE_GETDENTS || BFS_HAS_FDCLOSEDIR)
+#endif
+
+#if BFS_USE_UNWRAPDIR
+/**
+ * Detach the file descriptor from an open directory.
+ *
+ * @param dir
+ *         The directory to detach.
+ * @return
+ *         The file descriptor of the directory.
+ */
+int bfs_unwrapdir(struct bfs_dir *dir);
+#endif
+
+#endif // BFS_DIR_H