Unix for Beginners
Unix Shell Programming
Unix Useful References
Unix Useful Resources
Copyright © 2014 by tutorialspoint
ustat() - Unix, Linux System Call
ustat - get file system statistics
#include <unistd.h> /* libc */
#include <ustat.h> /* glibc2 */
int ustat(dev_t dev, struct ustat *ubuf);
ustat() returns information about a mounted file system.
dev is a device number identifying a device containing
a mounted file system.
ubuf is a pointer to a ustat structure that contains the following
daddr_t f_tfree; /* Total free blocks */
ino_t f_tinode; /* Number of free inodes */
char f_fname; /* Filsys name */
char f_fpack; /* Filsys pack name */
The last two fields, f_fname and f_fpack, are not implemented and will
always be filled with null bytes (\0).
On success, zero is returned and the ustat structure pointed to by
ubuf will be filled in. On error, -1 is returned, and
errno is set appropriately.
ubuf points outside of your accessible address space.
dev does not refer to a device containing a mounted file system.
The mounted file system referenced by
dev does not support this operation, or any version of Linux before
ustat() is deprecated and has only been provided for compatibility.
All new programs should use
The HP-UX version of the
ustat structure has an additional field,
f_blksize, that is unknown elsewhere.
For some file systems, the number of free inodes does not change.
Such file systems will return -1 in the field
f_tinode. For some file systems, inodes are dynamically allocated.
Such file systems will return the current number of free inodes.