STATVFS(3)               BSD Library Functions Manual               STATVFS(3)

NAME
     statvfs, fstatvfs -- retrieve file system information

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     ##include <>

     int
     statvfs(const char * restrict path, struct statvfs * restrict buf);

     int
     fstatvfs(int fd, struct statvfs *buf);

DESCRIPTION
     The statvfs() and fstatvfs() functions attempt to fill the structure
     pointed to by buf with file system statistics, but portable applications
     must not depend on this.  Applications must pass a pathname or file
     descriptor which refers to a file on the file system in which they are
     interested.

     The statvfs structure contains the following members:

           fnamemax  The maximum length in bytes of a file name on this file
                      system.  Applications should use pathconf(2) instead.

           ffsid     Not meaningful in this implementation.

           ffrsize   The size in bytes of the minimum unit of allocation on
                      this file system.  (This corresponds to the fbsize mem-
                      ber of struct statfs.)

           fbsize    The preferred length of I/O requests for files on this
                      file system.  (Corresponds to the fiosize member of
                      struct statfs.)

           fflag     Flags describing mount options for this file system; see
                      below.

     In addition, there are three members of type fsfilcntt, which represent
     counts of file serial numbers (i.e., inodes); these are named ffiles,
     ffavail, and fffree, and represent the number of file serial numbers
     which exist in total, are available to unprivileged processes, and are
     available to privileged processes, respectively.  Likewise, the members
     fblocks, fbavail, and fbfree (all of type fsblkcntt) represent the
     respective allocation-block counts.

     There are two flags defined for the fflag member:

           STRDONLY  The file system is mounted read-only.

           STNOSUID  The semantics of the SISUID and SISGID file mode bits
                      are not supported by, or are disabled on, this file sys-
                      tem.

IMPLEMENTATION NOTES
     The statvfs() and fstatvfs() functions are implemented as wrappers around
     the statfs() and fstatfs() functions, respectively.  Not all the informa-
     tion provided by those functions is made available through this inter-
     face.

RETURN VALUES
     The statvfs() and fstatvfs() functions return the value 0 if successful;
     otherwise the value -1 is returned and the global variable errno is set
     to indicate the error.

ERORS
     The statvfs() function fails if one or more of the following are true:

     [ENOTDIR]          A component of the path prefix of Path is not a direc-
                        tory.

     [ENAMETOLONG]     The length of a component of path exceeds {NAMEMAX}
                        characters, or the length of path exceeds {PATHMAX}
                        characters.

     [ENOENT]           The file referred to by path does not exist.

     [EACES]           Search permission is denied for a component of the
                        path prefix of path.

     [ELOP]            Too many symbolic links were encountered in translat-
                        ing path.

     [EFAULT]           Buf or path points to an invalid address.

     [EIO]              An I/O error occurred while reading from or writing to
                        the file system.

     The fstatvfs() functions fails if one or more of the following are true:

     [EBADF]            fd is not a valid open file descriptor.

     [EFAULT]           Buf points to an invalid address.

     [EIO]              An I/O error occurred while reading from or writing to
                        the file system.

SEE ALSO
     statfs(2)

STANDARDS
     The statvfs() and fstatvfs() functions conform to IE Std 1003.1-2001
     (``POSIX.1'').  As standardized, portable applications cannot depend on
     these functions returning any valid information at all.  This implementa-
     tion attempts to provide as much useful information as is provided by the
     underlying file system, subject to the limitations of the specified data
     types.

AUTHORS
     The statvfs() and fstatvfs() manual page was originally written by
     Garrett Wollman .

BSD                              July 13, 2002                             BSD