stat.h -- Header File

Definitions and declarations used to obtain file status
#include <sys/stat.h>

stat.h is  a header  file that declares  the structure stat  plus constants
used by  the routines that manipulate files,  directories, and named pipes.
It holds the prototypes for the routines chmod(), fstat(), mkdir(), stat(),
and umask().

The following summarizes the structure stat:

struct stat {
     dev_t          st_dev;        /* Device */
     ino_t          st_ino;        /* Inode number */
     mode_t         st_mode;       /* Mode */
     nlink_t        st_nlink;      /* Link count */
     uid_t          st_uid;        /* User id */
     gid_t          st_gid;        /* Group id */
     dev_t          st_rdev;       /* Real device; NB, this is non-POSIX */
     off_t          st_size;       /* Size */
     time_t         st_atime;      /* Access time */
     time_t         st_mtime;      /* Modify time */
     time_t         st_ctime;      /* Change time */
};

st_dev  and st_ino  together form  a unique description  of the  file.  The
former is the  device on which the file and  its i-node reside, whereas the
latter is the index number of the file.  st_mode gives the permission bits,
as outlined below.  st_nlink gives the number of links to the file.  st_uid
and  st_gid, respectively  given the  user id  and group  id of  the owner.
st_rdev, valid  only for special  files, holds the major  and minor numbers
for the file.   st_size gives the size of the  file, in bytes.  For a pipe,
the size is the number of bytes waiting to be read from the pipe.

Three entries for each file give  the last occurrences of various events in
the file's history.  st_atime gives time  the file was last read or written
to.  st_mtime  gives the  time of the  last modification, write  for files,
create or delete entry for  directories.  st_ctime gives the last change to
the attributes, not including times and size.

The following manifest constants define file types:

     S_IFMT    Type
     S_IFDIR   Directory
     S_IFCHR   Character-special file
     S_IFPIP   Pipe
     S_IFIFO   Pipe
     S_IFBLK   Block-special file
     S_IFREG   Regular file

The following manifest constants define file modes:

     S_IREAD   Read permission, owner
     S_IWRITE  Write permission, owner
     S_IEXEC   Execute/search permission, owner
     S_IRWXU   RWX permission, owner
     S_IRUSR   Read permission, owner
     S_IWUSR   Write permission, owner
     S_IXUSR   Execute/search permission, owner
     S_IRWXG   RWX permission, group
     S_IRGRP   Read permission, group
     S_IWGRP   Write permission, group
     S_IXGRP   Execute/search permission, group
     S_IRWXO   RWX permission, other
     S_IROTH   Read permission, other
     S_IWOTH   Write permission, other
     S_IXOTH   Execute/search permission, other

See Also

chmod(),
fstat(),
header file,
stat()
POSIX Standard, §5.6.1

© 2012 by Stephen A. Ness