ustat(S)

ustat -- get file system statistics

Syntax

cc . . . -lc

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

int ustat (dev, buf)
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 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 */
       char         f_fpack[6];  /* Filsys pack name */

The last two fields, f_fname and f_fpack may not have significant information on all systems, and, in that case, contain the null character.

The ustat system call fails if one or more of the following is true:

[ECOMM]: dev is on a remote machine and the link to that machine is no longer active.
[EFAULT]: buf points outside the process's allocated address space.
[EINTR]: A signal was caught during a ustat system call.
[EINVAL]: dev is not the device number of a device containing a mounted file system.

Notes

The ``f_tfree'' field of the ustat structure returns 512-byte blocks in UNIX binaries and 1024-byte blocks in XENIX binaries.

Diagnostics

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

Standards conformance