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

NAME
     fstatvfs, statvfs -- retrieve file system information

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <sys/statvfs.h>

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

     int
     statvfs(const char *restrict path, struct statvfs *restrict 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:

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

           f_fsid     Not meaningful in this implementation.

           f_frsize   The size in bytes of the minimum unit of allocation on this file system.  (This corre-sponds corresponds
                      sponds to the f_bsize member of struct statfs.)

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

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

     In addition, there are three members of type fsfilcnt_t, which represent counts of file serial numbers
     (i.e., inodes); these are named f_files, f_favail, and f_ffree, 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 f_blocks, f_bavail, and f_bfree (all of type
     fsblkcnt_t) represent the respective allocation-block counts.

     There are two flags defined for the f_flag member:

           ST_RDONLY  The file system is mounted read-only.

           ST_NOSUID  The semantics of the S_ISUID and S_ISGID file mode bits are not supported by, or are
                      disabled on, this file system.

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

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.

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

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

     [ELOOP]            Too many symbolic links were encountered in translating path.

     [ENAMETOOLONG]     The length of a component of path exceeds {NAME_MAX} characters, or the length of
                        path exceeds {PATH_MAX} characters.

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

     [ENOTDIR]          A component of the path prefix of Path is not a directory.

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

     [EBADF]            fildes 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 IEEE Std 1003.1-2001 (``POSIX.1'').  As standardized,
     portable applications cannot depend on these functions returning any valid information at all.  This
     implementation 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
     <wollman@FreeBSD.org>.

BSD                              July 13, 2002                             BSD