HP-UX Reference (11i v1 05/09) - 2 System Calls (vol 5)

ustat(2) ustat(2)

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 identi-

fying 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.