The Single UNIX ® Specification, Version 2
Copyright © 1997 The Open Group


fstat - get file status


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

int fstat(int fildes, struct stat *buf);


The fstat() function obtains information about an open file associated with the file descriptor fildes, and writes it to the area pointed to by buf.

If _XOPEN_REALTIME is defined and has a value other than -1, and fildes references a shared memory object, the implementation need update in the stat structure pointed to by the buf argument only the st_uid, st_gid, st_size, and st_mode fields, and only the S_IRUSR, S_IWUSR, S_IRGRP, S_IWGRP, S_IROTH, and S_IWOTH file permission bits need be valid.

The buf argument is a pointer to a stat structure, as defined in <sys/stat.h>, into which information is placed concerning the file.

The structure members st_mode, st_ino, st_dev, st_uid, st_gid, st_atime, st_ctime and st_mtime will have meaningful values for all file types defined in this document. The value of the member st_nlink will be set to the number of links to the file.

An implementation that provides additional or alternative file access control mechanisms may, under implementation-dependent conditions, cause fstat() to fail.

The fstat() function updates any time-related fields as described in File Times Update (see the XBD specification, Character Set ), before writing into the stat structure.


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


The fstat() function will fail if:
The fildes argument is not a valid file descriptor.
An I/O error occurred while reading from the file system.
The file size in bytes or the number of blocks allocated to the file or the file serial number cannot be represented correctly in the structure pointed to by buf.

The fstat() function may fail if:

One of the values is too large to store into the structure pointed to by the buf argument.








lstat(), stat(), <sys/stat.h>, <sys/types.h>.


Derived from Issue 1 of the SVID.

UNIX ® is a registered Trademark of The Open Group.
Copyright © 1997 The Open Group
[ Main Index | XSH | XCU | XBD | XCURSES | XNS ]