STATFS(2)                 OpenBSD Programmer's Manual                STATFS(2)

NAME
     statfs, fstatfs - get file system statistics

SYNOPSIS
     #include <sys/param.h>
     #include <sys/mount.h>

     int
     statfs(const char *path, struct statfs *buf);

     int
     fstatfs(int fd, struct statfs *buf);

DESCRIPTION
     statfs() returns information about a mounted file system.  path is the
     path name of any file within the mounted file system.  buf is a pointer
     to a statfs structure defined as follows:

     typedef struct { int32_t val[2]; } fsid_t;

     #define MFSNAMELEN   16 /* length of fs type name, including nul */
     #define MNAMELEN     90 /* length of buffer for returned name */

     struct statfs {
        u_int32_t       f_flags;        /* copy of mount flags */
        u_int32_t       f_bsize;        /* file system block size */
        u_int32_t       f_iosize;       /* optimal transfer block size */
                                        /* unit is f_bsize */
        u_int64_t       f_blocks;       /* total data blocks in file system */
        u_int64_t       f_bfree;        /* free blocks in fs */
        int64_t         f_bavail;       /* free blocks avail to non-superuser */
        u_int64_t       f_files;        /* total file nodes in file system */
        u_int64_t       f_ffree;        /* free file nodes in fs */
        int64_t         f_favail;       /* free file nodes avail to non-root */
        u_int64_t       f_syncwrites;   /* count of sync writes since mount */
        u_int64_t       f_syncreads;    /* count of sync reads since mount */
        u_int64_t       f_asyncwrites;  /* count of async writes since mount */
        u_int64_t       f_asyncreads;   /* count of async reads since mount */
        fsid_t          f_fsid;         /* file system id */
        u_int32_t       f_namemax;      /* maximum filename length */
        uid_t           f_owner;        /* user that mounted the file system */
        u_int32_t       f_ctime;        /* last mount [-u] time */
        u_int32_t       f_spare[3];     /* spare for later */
        char f_fstypename[MFSNAMELEN];  /* fs type name */
        char f_mntonname[MNAMELEN];     /* directory on which mounted */
        char f_mntfromname[MNAMELEN];   /* mounted file system */
        union mount_info mount_info;    /* per-filesystem mount options */
     };

     fstatfs() returns the same information about an open file referenced by
     descriptor fd.

     Note that f_fsid will be empty unless the user is the superuser.

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

ERRORS
     statfs() fails if one or more of the following are true:

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

     [ENAMETOOLONG]
                   The length of a component of path exceeds {NAME_MAX} char-
                   acters, or the length of path exceeds {PATH_MAX} charac-
                   ters.

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

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

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

     fstatfs() 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
     df(1), mount(2), stat(2)

HISTORY
     The statfs() function first appeared in 4.4BSD.

OpenBSD 4.5                      June 5, 2009                                2