NAME

ustat() − get mounted file system statistics

SYNOPSIS

#include <ustat.h>

int ustat(dev_t dev, struct ustat *buf);

DESCRIPTION

The ustat() system call returns information about a mounted file system.  dev is a device number identifying a device containing a mounted file system.  buf is a pointer to a ustat structure (defined in <ustat.h>) that includes the following elements:

daddr_t  f_tfree;        /* Total free blocks */
ino_t    f_tinode;       /* Number of free inodes */
char     f_fname[6];     /* Filsys name or null */
char     f_fpack[6];     /* Filsys pack name or null */
int      f_blksize;      /* Block size */

The value of f_tfree is the number of free blocks of size f_blksize. 

RETURN VALUE

ustat() returns the following values:

 0 Successful completion. 

-1 Failure.  errno is set to indicate the error. 

ERRORS

If ustat() fails, errno is set to one of the following values. 

[EFAULT] buf points outside the process’s allocated address space.  The reliable detection of this error is implementation dependent. 

[EINVAL] dev is not the device number of a device containing a mounted file system. 

WARNINGS

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, the inodes can be dynamically allocated.  For such file systems, the field f_tinode contains the number of free inodes at the current time. 

AUTHOR

ustat() was developed by AT&T and HP. 

SEE ALSO

touch(1), stat(2), statvfs(2), fs(4), fs_vxfs(4). 

STANDARDS CONFORMANCE

ustat(): SVID2, SVID3, XPG2

Hewlett-Packard Company  —  HP-UX Release 10.20:  July 1996