/**************************************************************************** * bfs * * Copyright (C) 2018-2019 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. * ****************************************************************************/ /** * A facade over the stat() API that unifies some details that diverge between * implementations, like the names of the timespec fields and the presence of * file "birth" times. On new enough Linux kernels, the facade is backed by * statx() instead, and so it exposes a similar interface with a mask for which * fields were successfully returned. */ #ifndef BFS_STAT_H #define BFS_STAT_H #include "config.h" #include <sys/types.h> #include <time.h> #if BFS_USE_SYS_PARAM_H # include <sys/param.h> #endif /** * bfs_stat field bitmask. */ enum bfs_stat_field { BFS_STAT_DEV = 1 << 0, BFS_STAT_INO = 1 << 1, BFS_STAT_TYPE = 1 << 2, BFS_STAT_MODE = 1 << 3, BFS_STAT_NLINK = 1 << 4, BFS_STAT_GID = 1 << 5, BFS_STAT_UID = 1 << 6, BFS_STAT_SIZE = 1 << 7, BFS_STAT_BLOCKS = 1 << 8, BFS_STAT_RDEV = 1 << 9, BFS_STAT_ATTRS = 1 << 10, BFS_STAT_ATIME = 1 << 11, BFS_STAT_BTIME = 1 << 12, BFS_STAT_CTIME = 1 << 13, BFS_STAT_MTIME = 1 << 14, }; /** * Get the human-readable name of a bfs_stat field. */ const char *bfs_stat_field_name(enum bfs_stat_field field); /** * bfs_stat() flags. */ enum bfs_stat_flags { /** Follow symlinks (the default). */ BFS_STAT_FOLLOW = 0, /** Never follow symlinks. */ BFS_STAT_NOFOLLOW = 1 << 0, /** Try to follow symlinks, but fall back to the link itself if broken. */ BFS_STAT_TRYFOLLOW = 1 << 1, /** Try to use cached values without synchronizing remote filesystems. */ BFS_STAT_NOSYNC = 1 << 2, }; #ifdef DEV_BSIZE # define BFS_STAT_BLKSIZE DEV_BSIZE #elif defined(S_BLKSIZE) # define BFS_STAT_BLKSIZE S_BLKSIZE #else # define BFS_STAT_BLKSIZE 512 #endif /** * Facade over struct stat. */ struct bfs_stat { /** Bitmask indicating filled fields. */ enum bfs_stat_field mask; /** Device ID containing the file. */ dev_t dev; /** Inode number. */ ino_t ino; /** File type and access mode. */ mode_t mode; /** Number of hard links. */ nlink_t nlink; /** Owner group ID. */ gid_t gid; /** Owner user ID. */ uid_t uid; /** File size in bytes. */ off_t size; /** Number of disk blocks allocated (of size BFS_STAT_BLKSIZE). */ blkcnt_t blocks; /** The device ID represented by this file. */ dev_t rdev; /** Attributes/flags set on the file. */ unsigned long long attrs; /** Access time. */ struct timespec atime; /** Birth/creation time. */ struct timespec btime; /** Status change time. */ struct timespec ctime; /** Modification time. */ struct timespec mtime; }; /** * Facade over fstatat(). * * @param at_fd * The base file descriptor for the lookup. * @param at_path * The path to stat, relative to at_fd. Pass NULL to fstat() at_fd * itself. * @param flags * Flags that affect the lookup. * @param[out] buf * A place to store the stat buffer, if successful. * @return * 0 on success, -1 on error. */ int bfs_stat(int at_fd, const char *at_path, enum bfs_stat_flags flags, struct bfs_stat *buf); /** * Get a particular time field from a bfs_stat() buffer. */ const struct timespec *bfs_stat_time(const struct bfs_stat *buf, enum bfs_stat_field field); /** * A unique ID for a file. */ typedef unsigned char bfs_file_id[sizeof(dev_t) + sizeof(ino_t)]; /** * Compute a unique ID for a file. */ void bfs_stat_id(const struct bfs_stat *buf, bfs_file_id *id); #endif // BFS_STAT_H