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STAT(2)			  FreeBSD System Calls Manual		       STAT(2)

     stat, lstat, fstatat, fstat -- get	file status

     #include <sys/types.h>
     #include <sys/stat.h>
     #include <fcntl.h>

     stat(const	char *path, struct stat	*sb);

     lstat(const char *path, struct stat *sb);

     fstatat(int fd, const char	*path, struct stat *sb,	int flag);

     fstat(int fd, struct stat *sb);

     The stat()	function obtains information about the file pointed to by
     path.  Read, write, or execute permission of the named file is not
     required, but all directories listed in the path name leading to the file
     must be searchable.

     The lstat() function is identical to stat() except	when the named file is
     a symbolic	link, in which case lstat() returns information	about the link
     itself, not the file the link references.

     The fstatat() function is equivalent to either the	stat() or lstat()
     function depending	on the value of	flag (see below), except that where
     path specifies a relative path, the file whose information	is returned is
     determined	relative to the	directory associated with file descriptor fd
     instead of	the current working directory.

     If	fstatat() is passed the	special	value AT_FDCWD (defined	in <fcntl.h>)
     in	the fd parameter, the current working directory	is used	and the	behav-
     ior is identical to a call	to stat() or lstat(), depending	on whether or
     not the AT_SYMLINK_NOFOLLOW bit is	set in flag.

     Values for	flag are constructed by	bitwise-inclusive ORing	flags from the
     following list defined in <fcntl.h>:

	   AT_SYMLINK_NOFOLLOW	If path	names a	symbolic link, then the	status
				of the symbolic	link is	returned.

     The fstat() function obtains the same information about an	open file
     known by the file descriptor fd.

     The sb argument is	a pointer to a stat() structure	as defined by
     <sys/stat.h> (shown below)	and into which information is placed concern-
     ing the file.

     struct stat {
	 dev_t	    st_dev;    /* inode's device */
	 ino_t	    st_ino;    /* inode's number */
	 mode_t	    st_mode;   /* inode	protection mode	*/
	 nlink_t    st_nlink;  /* number of hard links */
	 uid_t	    st_uid;    /* user ID of the file's	owner */
	 gid_t	    st_gid;    /* group	ID of the file's group */
	 dev_t	    st_rdev;   /* device type */
	 struct	timespec st_atim;  /* time of last access */
	 struct	timespec st_mtim;  /* time of last data	modification */
	 struct	timespec st_ctim;  /* time of last file	status change */
	 off_t	    st_size;   /* file size, in	bytes */
	 int64_t    st_blocks; /* blocks allocated for file */
	 u_int32_t  st_blksize;/* optimal blocksize for	I/O */
	 u_int32_t  st_flags;  /* user defined flags for file */
	 u_int32_t  st_gen;    /* file generation number */

     The time-related fields of	struct stat are	represented in struct timespec
     format, which has nanosecond precision.  However, the actual precision is
     generally limited by the file system holding the file.  The fields	are as

     st_atim	 Time when file	data was last accessed.	 Set when the file
		 system	object was created and updated by the utimes(2)	and
		 read(2) system	calls.

     st_mtim	 Time when file	data was last modified.	 Changed by the
		 truncate(2), utimes(2), and write(2) system calls.  For
		 directories, changed by any system call that alters which
		 files are in the directory, such as the unlink(2), rename(2),
		 mkdir(2), and symlink(2) system calls.

     st_ctim	 Time when file	status was last	changed	(inode data modifica-
		 tion).	 Changed by the	chmod(2), chown(2), link(2),
		 rename(2), unlink(2), utimes(2), and write(2) system calls.

     In	addition, all the time fields are set to the current time when a file
     system object is first created by the mkdir(2), mkfifo(2),	mknod(2),
     open(2), and symlink(2) system calls.

     For compatibility with previous standards,	st_atime, st_mtime, and
     st_ctime macros are provided that expand to the tv_secs member of their
     respective	struct timespec	member.	 Deprecated macros are also provided
     for some transitional names: st_atimensec,	st_mtimensec, st_ctimensec,
     st_atimespec, st_mtimespec, and st_ctimespec

     The size-related fields of	the struct stat	are as follows:

     st_blksize	    The	optimal	I/O block size for the file.

     st_blocks	    The	actual number of blocks	allocated for the file in
		    512-byte units.  As	short symbolic links are stored	in the
		    inode, this	number may be zero.

     The status	information word st_mode has the following bits:

	   #define S_IFMT   0170000  /*	type of	file mask */
	   #define S_IFIFO  0010000  /*	named pipe (fifo) */
	   #define S_IFCHR  0020000  /*	character special */
	   #define S_IFDIR  0040000  /*	directory */
	   #define S_IFBLK  0060000  /*	block special */
	   #define S_IFREG  0100000  /*	regular	*/
	   #define S_IFLNK  0120000  /*	symbolic link */
	   #define S_IFSOCK 0140000  /*	socket */
	   #define S_ISUID  0004000  /*	set-user-ID on execution */
	   #define S_ISGID  0002000  /*	set-group-ID on	execution */
	   #define S_ISVTX  0001000  /*	save swapped text even after use */
	   #define S_IRWXU  0000700  /*	RWX mask for owner */
	   #define S_IRUSR  0000400  /*	R for owner */
	   #define S_IWUSR  0000200  /*	W for owner */
	   #define S_IXUSR  0000100  /*	X for owner */
	   #define S_IRWXG  0000070  /*	RWX mask for group */
	   #define S_IRGRP  0000040  /*	R for group */
	   #define S_IWGRP  0000020  /*	W for group */
	   #define S_IXGRP  0000010  /*	X for group */
	   #define S_IRWXO  0000007  /*	RWX mask for other */
	   #define S_IROTH  0000004  /*	R for other */
	   #define S_IWOTH  0000002  /*	W for other */
	   #define S_IXOTH  0000001  /*	X for other */

     The following macros test a file's	type.  If the file is of that type, a
     non-zero value is returned; otherwise, 0 is returned.

	   S_ISBLK(st_mode m)  /* block	special	*/
	   S_ISCHR(st_mode m)  /* char special */
	   S_ISDIR(st_mode m)  /* directory */
	   S_ISFIFO(st_mode m) /* fifo */
	   S_ISLNK(st_mode m)  /* symbolic link	*/
	   S_ISREG(st_mode m)  /* regular file */
	   S_ISSOCK(st_mode m) /* socket */

     For a list	of access modes, see <sys/stat.h>, access(2), and chmod(2).

     Upon successful completion	a value	of 0 is	returned.  Otherwise, a	value
     of	-1 is returned and errno is set	to indicate the	error.

     stat(), lstat(), and fstatat() will fail if:

     [ENOTDIR]		A component of the path	prefix is not a	directory.

     [ENAMETOOLONG]	A component of a pathname exceeded NAME_MAX charac-
			ters, or an entire path	name exceeded PATH_MAX charac-

     [ENOENT]		The named file does not	exist.

     [EACCES]		Search permission is denied for	a component of the
			path prefix.

     [ELOOP]		Too many symbolic links	were encountered in translat-
			ing the	pathname.

     [EFAULT]		sb or name points to an	invalid	address.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

     Additionally, fstatat() will fail if:

     [EBADF]		The path argument does not specify an absolute path
			and the	fd argument is neither AT_FDCWD	nor a valid
			file descriptor	open for reading.

     fstat() will fail if:

     [EBADF]		fd is not a valid open file descriptor.

     [EFAULT]		sb points to an	invalid	address.

     [EIO]		An I/O error occurred while reading from or writing to
			the file system.

     chmod(2), chown(2), utimes(2), symlink(7)

     Previous versions of the system used different types for the st_dev,
     st_uid, st_gid, st_rdev, st_size, st_blksize, and st_blocks fields.

     The stat(), lstat(), fstatat(), and fstat() function calls	are expected
     to	conform	to IEEE	Std 1003.1-1988	(``POSIX.1'').

     The stat()	and fstat() system calls first appeared	in Version 1 AT&T
     UNIX.  The	<sys/stat.h> header file and the struct	stat were introduced
     in	Version	7 AT&T UNIX.

     An	lstat()	function call appeared in 4.2BSD.  The fstatat() function
     appeared in OpenBSD 5.0.

     The file generation number, st_gen, is only available to the superuser.

     Certain programs written when the timestamps were just of type time_t
     assumed that the members were consecutive (and could therefore be placed
     directly to utimes(2)).  The transition to	timestamps of type struct
     timespec broke them irrevocably.

     Applying fstat() to a socket (and thus to a pipe) returns a zeroed
     buffer, except for	the blocksize field, and a unique device and inode

FreeBSD	11.1		       November	19, 2017		  FreeBSD 11.1


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