STAT(2)                   386BSD Programmer's Manual                   STAT(2)

NAME
     stat, lstat, fstat - get file status

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

     int
     stat(const char *path, struct stat *buf)

     int
     lstat(const char *path, struct stat *buf)

     int
     fstat(int fd, struct stat *buf)

DESCRIPTION
     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 seachable.

     Lstat() is like stat() except in the case where the named file is a
     symbolic link, in which case lstat() returns information about the link,
     while stat() returns information about the file the link references.

     The fstat() obtains the same information about an open file known by the
     file descriptor fd, such as would be obtained by an open call.

     Buf is a pointer to a stat() structure as defined by <sys/stat.h> (shown
     below) and into which information is placed concerning 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 */
         off_t    st_size;   /* file size, in bytes */
         time_t   st_atime;  /* time of last access */
         long     st_spare1;
         time_t   st_mtime;  /* time of last data modification */
         long     st_spare2;
         time_t   st_ctime;  /* time of last file status change */
         long     st_spare3;
         long     st_blksize;/* optimal file sys I/O ops blocksize */
         long     st_blocks; /* blocks allocated for file */
         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 following
                system calls: mknod(2),  utimes(2),  and read(2).

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

     st_ctime   Time when file status was last changed (inode data
                modification).  Changed by the following system calls:
                chmod(2) chown(2),  link(2),  mknod(2),  rename(2),
                unlink(2),  utimes(2),  write(2).

     st_blocks  The actual number of blocks allocated for the file in 512-byte
                units.

     The status information word st_mode has 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).

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

ERRORS
     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
                     set.

     [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
                     prefix.

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

     [EFAULT]        Buf 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]  Buf points to an invalid address.

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

CAVEAT
     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)).

SEE ALSO
     chmod(2),  chown(2),  utimes(2)

BUGS
     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.

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

HISTORY
     A lstat function call appeared in 4.2BSD.

4th Berkeley Distribution       March 10, 1991                               3