Retro video games delivered to your door every month!
Click above to get retro games delivered to your door ever month!
X-Hacker.org- libc - <b>stat</b> http://www.X-Hacker.org [<<Previous Entry] [^^Up^^] [Next Entry>>] [Menu] [About The Guide]
stat
====

Syntax
------

     #include <sys/stat.h>
     
     int stat(const char *file, struct stat *sbuf);

Description
-----------

This function obtains the status of the file FILE and stores it in
SBUF, which has this structure:

     struct  stat {
             time_t   st_atime;     /* time of last modification */
             time_t   st_ctime;     /*            ''             */
             dev_t    st_dev;       /* The drive number (0 = a:) */
             gid_t    st_gid;       /* getgid() */
             ino_t    st_ino;       /* starting cluster or a unique identifier */
             mode_t   st_mode;      /* file mode - S_IF* and S_IRUSR/S_IWUSR */
             time_t   st_mtime;     /*            ''             */
             nlink_t  st_nlink;     /* 2 + number of subdirs, or 1 for files */
             off_t    st_size;      /* size of file in bytes */
             off_t    st_blksize;   /* the size of transfer buffer */
             uid_t    st_uid;       /* getuid() */
     };

Return Value
------------

Zero on success, nonzero on failure (and ERRNO set).

Example
-------

     struct stat s;
     stat("data.txt", &s);
     if (S_ISDIR(s.st_mode))
       printf("is directory\n");

Implementation Notes
--------------------

Supplying a 100% Unix-compatible `f?stat()' functions under DOS is an
implementation nightmare.  The following notes describe some of the
obscure points specific to their behavior in DJGPP.

1. The `drive' for character devices (like `con', `/dev/nul' and others
is returned as -1.  For drives networked by Novell Netware, it is
returned as -2.

2. The starting cluster number of a file serves as its inode number.
For files whose starting cluster number is inaccessible (empty files,
files on networked drives, etc.) the `st_inode' field will be `invented'
in a way which guarantees that no two different files will get the same
inode number (thus it is unique).  This invented inode will also be
different from any real cluster number of any local file.  However, only
for local, non-empty files/directories the inode is guaranteed to be
consistent between `stat()' and `fstat()' function calls.

3. The WRITE access mode bit is set only for the user (unless the file
is read-only, hidden or system).  EXECUTE bit is set for directories,
files which can be executed from the DOS prompt (batch files, .com,
.dll and .exe executables) or run by go32 extender.

4. Size of directories is reported as the number of its files (sans `.'
and `..' entries) multiplied by 32 bytes (the size of directory entry).
On FAT filesystems that support the LFN API (such as Windows 9x), the
reported size of the directory accounts for additional space used to
store the long filenames.

5. Time stamp for root directories is taken from the volume label entry,
if that's available; otherwise, it is reported as 1-Jan-1980.

6. The variable _djstat_flags: controls what hard-to-get fields   
of `struct stat' are needed by the application.

7. `stat()' should not be used to get an up-to-date info about a file
which is open and has been written to, because `stat()' will only
return correct data after the file is closed.  Use fstat: while   
the file is open.

8. The number of links `st_nlink' is always 1 for files other than
directories.  For directories, it is the number of subdirectories plus
2.  This is so that programs written for Unix that depend on this to
optimize recursive traversal of the directory tree, will still work.


See Also: _djstat_flags fstat

Online resources provided by: http://www.X-Hacker.org --- NG 2 HTML conversion by Dave Pearson