USTAT(2)                  (2019-03-06)                   USTAT(2)

     NAME
          ustat - get filesystem statistics

     SYNOPSIS
          #include <sys/types.h>
          #include <unistd.h>    /* libc[45] */
          #include <ustat.h>     /* glibc2 */

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

     DESCRIPTION
          ustat() returns information about a mounted filesystem.  dev
          is a device number identifying a device containing a mounted
          filesystem.  ubuf is a pointer to a ustat structure that
          contains the following members:

              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, are not imple-
          mented and will always be filled with null bytes (aq\0aq).

     RETURN VALUE
          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.

     ERRORS
          EFAULT
               ubuf points outside of your accessible address space.

          EINVAL
               dev does not refer to a device containing a mounted
               filesystem.

          ENOSYS
               The mounted filesystem referenced by dev does not sup-
               port this operation, or any version of Linux before
               1.3.16.

     VERSIONS
          Since version 2.28, glibc no longer provides a wrapper for
          this system call.

     CONFORMING TO
          SVr4.

     NOTES

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     USTAT(2)                  (2019-03-06)                   USTAT(2)

          ustat() is deprecated and has been provided only for compat-
          ibility.  All new programs should use statfs(2) instead.

        HP-UX notes
          The HP-UX version of the ustat structure has an additional
          field, f_blksize, that is unknown elsewhere.  HP-UX warns:
          For some filesystems, the number of free inodes does not
          change.  Such filesystems will return -1 in the field
          f_tinode. For some filesystems, inodes are dynamically allo-
          cated.  Such filesystems will return the current number of
          free inodes.

     SEE ALSO
          stat(2), statfs(2)

     COLOPHON
          This page is part of release 5.10 of the Linux man-pages
          project.  A description of the project, information about
          reporting bugs, and the latest version of this page, can be
          found at https://www.kernel.org/doc/man-pages/.

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