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 fildes, struct stat *buf);

DESCRIPTION

path points to a path name naming a file. 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. stat obtains information about the named file.

Note that in a Remote File Sharing environment, the information returned by stat depends on the user/group mapping set up between the local and remote computers. [See idload(1M).] lstat obtains file attributes similar to stat, except when the named file is a symbolic link; in that case lstat returns information about the link, while stat returns information about the file the link references.

fstat obtains information about an open file known by the file descriptor fildes, obtained from a successful open, creat, dup, fcntl, or pipe system call.

buf is a pointer to a stat structure into which information is placed concerning the file.

The contents of the structure pointed to by buf include  the
following members:
     mode_t   st_mode;     /* File mode [see mknod(2)] */
     ino_t    st_ino;      /* Inode number */
     dev_t    st_dev;      /* ID of device containing */
                           /* a directory entry for this file */
     dev_t    st_rdev;     /* ID of device */
                           /* This entry is defined only for */
                           /* char special or block special files */
     nlink_t  st_nlink;    /* Number of links */
     uid_t    st_uid;      /* User ID of the file's owner */
     gid_t    st_gid;      /* Group ID of the file's group */
     off_t    st_size;     /* File size in bytes */
     time_t   st_atime;    /* Time of last access */
     time_t   st_mtime;    /* Time of last data modification */
     time_t   st_ctime;    /* Time of last file status change */

                           /* Times measured in seconds since */
                           /* 00:00:00 UTC, Jan. 1, 1970 */
     long     st_blksize;  /* Preferred I/O block size */
     long     st_blocks;   /* Number st_blksize blocks allocated */

st_mode The mode of the file as described in mknod(2). In addition to the modes described in mknod(2), the mode of a file may also be S_IFLNK if the file is a symbolic link. (Note that S_IFLNK may only be returned by lstat.)

st_ino This field uniquely identifies the file in a given file system. The pair st_ino and st_dev uniquely identifies regular files.

st_dev This field uniquely identifies the file system that contains the file. Its value may be used as input to the ustat system call to determine more information about this file system. No other meaning is associated with this value.

st_rdev This field should be used only by administrative commands. It is valid only for block special or character special files and only has meaning on the system where the file was configured.

st_nlink This field should be used only by administrative commands.

st_uid The user ID of the file's owner.

st_gid The group ID of the file's group.

st_size For regular files, this is the address of the end of the file. For block special or character special, this is not defined. See also pipe(2).

st_atime Time when file data was last accessed. Changed by the following system calls: creat, mknod, pipe, utime, and read.

st_mtime Time when data was last modified. Changed by the following system calls: creat, mknod, pipe, utime, and write.

st_ctime Time when file status was last changed. Changed by the following system calls: chmod, chown, creat, link, mknod, pipe, unlink, utime, and write.

st_blksize

          A  hint  as  to  the  "best"  unit  size  for  I/O
          operations.   This field is not defined for block-
          special or character-special files.

st_blocks The total number of physical blocks  of  size  512
          bytes  actually  allocated on disk.  This field is
          not defined for block-special or character-special
          files.

stat and lstat fail if one or more of the following are true:

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

EFAULT buf or path points to an invalid address.

EINTR A signal was caught during the stat or lstat system call.

ELOOP Too many symbolic links were encountered in translating path.

EMULTIHOP Components of path require hopping to multiple remote machines and the file system does not allow it.

ENAMETOOLONG The length of the path argument exceeds {PATH_MAX}, or the length of a path component exceeds {NAME_MAX} while _POSIX_NO_TRUNC is in effect.

ENOENT The named file does not exist or is the null pathname.

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

ENOLINK path points to a remote machine and the link to that machine is no longer active.

EOVERFLOW A component is too large to store in the structure pointed to by buf.

fstat fails if one or more of the following are true:

EBADF fildes is not a valid open file descriptor.

EFAULT buf points to an invalid address.

EINTR A signal was caught during the fstat system call.

ENOLINK fildes points to a remote machine and the link to that machine is no longer active.

EOVERFLOW A component is too large to store in the structure pointed to by buf.

SEE ALSO

chmod(2), chown(2), creat(2),  link(2),  mknod(2),  pipe(2),
read(2),    time(2),    unlink(2),    utime(2),    write(2),
fattach(3C), stat(5).

DIAGNOSTICS

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