NAME

     statfs — get file system statistics

LIBRARY

     Standard C Library (libc, -lc)

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

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

     typedef struct fsid { int32_t val[2]; } fsid_t; /* file system id type */

     /*
      * filesystem statistics
      */

     #define MFSNAMELEN      16              /* length of type name including null */
     #define MNAMELEN        1024            /* size of on/from name bufs */
     #define STATFS_VERSION  0x20140518      /* current version number */

     struct statfs {
     uint32_t f_version;             /* structure version number */
     uint32_t f_type;                /* type of filesystem */
     uint64_t f_flags;               /* copy of mount exported flags */
     uint64_t f_bsize;               /* filesystem fragment size */
     uint64_t f_iosize;              /* optimal transfer block size */
     uint64_t f_blocks;              /* total data blocks in filesystem */
     uint64_t f_bfree;               /* free blocks in filesystem */
     int64_t  f_bavail;              /* free blocks avail to non-superuser */
     uint64_t f_files;               /* total file nodes in filesystem */
     int64_t  f_ffree;               /* free nodes avail to non-superuser */
     uint64_t f_syncwrites;          /* count of sync writes since mount */
     uint64_t f_asyncwrites;         /* count of async writes since mount */
     uint64_t f_syncreads;           /* count of sync reads since mount */
     uint64_t f_asyncreads;          /* count of async reads since mount */
     uint64_t f_spare[10];           /* unused spare */
     uint32_t f_namemax;             /* maximum filename length */
     uid_t     f_owner;              /* user that mounted the filesystem */
     fsid_t    f_fsid;               /* filesystem id */
     char      f_charspare[80];          /* spare string space */
     char      f_fstypename[MFSNAMELEN]; /* filesystem type name */
     char      f_mntfromname[MNAMELEN];  /* mounted filesystem */
     char      f_mntonname[MNAMELEN];    /* directory on which mounted */
     };

     The flags that may be returned include:

     MNT_RDONLY       The file system is mounted read-only; Even the super-user may not write on
                      it.

     MNT_NOEXEC       Files may not be executed from the file system.

     MNT_NOSUID       Setuid and setgid bits on files are not honored when they are executed.

     MNT_SYNCHRONOUS  All I/O to the file system is done synchronously.

     MNT_ASYNC        No file system I/O is done synchronously.

     MNT_SOFTDEP      Soft updates being done (see ffs(7)).

     MNT_GJOURNAL     Journaling with gjournal is enabled (see gjournal(8)).

     MNT_SUIDDIR      Special handling of SUID bit on directories.

     MNT_UNION        Union with underlying file system.

     MNT_NOSYMFOLLOW  Symbolic links are not followed.

     MNT_NOCLUSTERR   Read clustering is disabled.

     MNT_NOCLUSTERW   Write clustering is disabled.

     MNT_MULTILABEL   Mandatory Access Control (MAC) support for individual objects (see mac(4)).

     MNT_ACLS         Access Control List (ACL) support enabled.

     MNT_LOCAL        The file system resides locally.

     MNT_QUOTA        The file system has quotas enabled on it.

     MNT_ROOTFS       Identifies the root file system.

     MNT_EXRDONLY     The file system is exported read-only.

     MNT_NOATIME      Updating of file access times is disabled.

     MNT_USER         The file system has been mounted by a user.

     MNT_EXPORTED     The file system is exported for both reading and writing.

     MNT_DEFEXPORTED  The file system is exported for both reading and writing to any Internet
                      host.

     MNT_EXPORTANON   The file system maps all remote accesses to the anonymous user.

     MNT_EXKERB       The file system is exported with Kerberos uid mapping.

     MNT_EXPUBLIC     The file system is exported publicly (WebNFS).

     Fields that are undefined for a particular file system are set to -1.  The fstatfs() system
     call returns the same information about an open file referenced by descriptor fd.

RETURN VALUES

     Upon successful completion, the value 0 is returned; otherwise the value -1 is returned and
     the global variable errno is set to indicate the error.

ERRORS

     The statfs() system call 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 255 characters, or the length
                        of path exceeds 1023 characters.

     [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]           The buf or path argument points to an invalid address.

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

     [EINTEGRITY]       Corrupted data was detected while reading from the file system.

     The fstatfs() system call fails if one or more of the following are true:

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

     [EFAULT]           The buf argument points to an invalid address.

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

     [EINTEGRITY]       Corrupted data was detected while reading from the file system.

SEE ALSO

     fhstatfs(2), getfsstat(2)

HISTORY

     The statfs() system call first appeared in 4.4BSD.