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

     stat, lstat, fstat	-- get file status

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

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

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

     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.

     Lstat() is	like stat() except in the case where the named file is a sym-
     bolic link, in which case lstat() returns information about the link,
     while stat() returns information about the	file the link references.
     Unlike other filesystem objects, symbolic links do	not have an owner,
     group, access mode, times,	etc.  Instead, these attributes	are taken from
     the directory that	contains the link.  The	only attributes	returned from
     an	lstat()	that refer to the symbolic link	itself are the file type
     (S_IFLNK),	size, blocks, and link count (always 1).

     The fstat() 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;    /*	device inode resides on	*/
	 ino_t	  st_ino;    /*	inode's	number */
	 mode_t	  st_mode;   /*	inode protection mode */
	 nlink_t  st_nlink;  /*	number or hard links to	the file */
	 uid_t	  st_uid;    /*	user-id	of owner */
	 gid_t	  st_gid;    /*	group-id of owner */
	 dev_t	  st_rdev;   /*	device type, for special file inode */
	 struct	timespec st_atimespec;	/* time	of last	access */
	 struct	timespec st_mtimespec;	/* time	of last	data modification */
	 struct	timespec st_ctimespec;	/* time	of last	file status change */
	 off_t	  st_size;   /*	file size, in bytes */
	 quad_t	  st_blocks; /*	blocks allocated for file */
	 u_long	  st_blksize;/*	optimal	file sys I/O ops blocksize */
	 u_long	  st_flags;  /*	user defined flags for file */
	 u_long	  st_gen;    /*	file generation	number */

     The time-related fields of	struct stat are	as follows:

     st_atime	  Time when file data last accessed.  Changed by the mknod(2),
		  utimes(2) and	read(2)	system calls.

     st_mtime	  Time when file data last modified.  Changed by the mknod(2),
		  utimes(2) and	write(2) system	calls.

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

     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 */
     #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_IRUSR 0000400  /* read permission, owner	*/
     #define S_IWUSR 0000200  /* write permission, owner */
     #define S_IXUSR 0000100  /* execute/search	permission, owner */

     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.

     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.

     Stat() and	lstat()	will fail if:

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

     [EINVAL]	     The pathname contains a character with the	high-order bit

     [ENAMETOOLONG]  A component of a pathname exceeded	255 characters,	or an
		     entire path name exceeded 1023 characters.

     [ENOENT]	     The named file does not exist.

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

     [ELOOP]	     Too many symbolic links were encountered in translating
		     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.

     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

     The fields	in the stat structure currently	marked st_spare1, st_spare2,
     and st_spare3 are present in preparation for inode	time stamps expanding
     to	64 bits.  This,	however, can break certain programs that depend	on the
     time stamps being contiguous (in calls to utimes(2)).

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

     Applying fstat to a socket	(and thus to a pipe) returns a zero'd buffer,
     except for	the blocksize field, and a unique device and inode number.

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

     A lstat function call appeared in 4.2BSD.

4th Berkeley Distribution	April 19, 1994	     4th Berkeley Distribution


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