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STATFS(2)                   BSD System Calls Manual                  STATFS(2)

NAME
     statfs, statfs64, fstatfs, fstatfs64 -- get file system statistics

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

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

     int
     statfs64(const char *path, struct statfs64 *buf);

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

     int
     fstatfs64(int fd, struct statfs64 *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 or statfs64 structure defined as follows:

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

     #define MFSNAMELEN      15 /* length of fs type name, not inc. nul */
     #define MNAMELEN        90 /* length of buffer for returned name */
     #define MFSTYPENAMELEN  16 /* length of fs type name including null */
     #define MAXPATHLEN      1024

     struct statfs {
         short   f_otype;    /* type of file system (reserved: zero) */
         short   f_oflags;   /* copy of mount flags (reserved: zero) */
         long    f_bsize;    /* fundamental file system block size */
         long    f_iosize;   /* optimal transfer block size */
         long    f_blocks;   /* total data blocks in file system */
         long    f_bfree;    /* free blocks in fs */
         long    f_bavail;   /* free blocks avail to non-superuser */
         long    f_files;    /* total file nodes in file system */
         long    f_ffree;    /* free file nodes in fs */
         fsid_t  f_fsid;     /* file system id */
         uid_t   f_owner;    /* user that mounted the file system */
         short   f_reserved1;        /* reserved for future use */
         short   f_type;     /* type of file system (reserved) */
         long    f_flags;    /* copy of mount flags (reserved) */
         long    f_reserved2[2];     /* reserved for future use */
         char    f_fstypename[MFSNAMELEN]; /* fs type name */
         char    f_mntonname[MNAMELEN];    /* directory on which mounted */
         char    f_mntfromname[MNAMELEN];  /* mounted file system */
         char    f_reserved3;        /* reserved for future use */
         long    f_reserved4[4];     /* reserved for future use */
     };

     struct statfs64 {
         uint32_t        f_bsize;        /* fundamental file system block size */
         int32_t         f_iosize;       /* optimal transfer block size */
         uint64_t        f_blocks;       /* total data blocks in file system */
         uint64_t        f_bfree;        /* free blocks in fs */
         uint64_t        f_bavail;       /* free blocks avail to non-superuser */
         uint64_t        f_files;        /* total file nodes in file system */
         uint64_t        f_ffree;        /* free file nodes in fs */
         fsid_t          f_fsid;         /* file system id */
         uid_t           f_owner;        /* user that mounted the filesystem */
         uint32_t        f_type;         /* type of filesystem */
         uint32_t        f_flags;        /* copy of mount exported flags */
         uint32_t        f_fssubtype;    /* fs sub-type (flavor) */
         char            f_fstypename[MFSTYPENAMELEN];   /* fs type name */
         char            f_mntonname[MAXPATHLEN];        /* directory on which mounted */
         char            f_mntfromname[MAXPATHLEN];      /* mounted filesystem */
         uint32_t        f_reserved[8];  /* For future use */
     };

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

FLAGS
     These are some of the flags that may be present in the f_flags field.

     MNT_RDONLY             A read-only filesystem

     MNT_SYNCHRONOUS        File system is written to synchronously

     MNT_NOEXEC             Can't exec from filesystem

     MNT_NOSUID             Setuid bits are not honored on this filesystem

     MNT_NODEV              Don't interpret special files

     MNT_UNION              Union with underlying filesysten

     MNT_ASYNC              File system written to asynchronously

     MNT_EXPORTED           File system is exported File system is stored locally

     MNT_QUOTA              Quotas are enabled on this file system

     MNT_ROOTFS             This file system is the root of the file system

     MNT_DOVOLFS            File system supports volfs

     MNT_DONTBROWSE         File system is not appropriate path to user data

     MNT_UNKNOWNPERMISSIONS
                            VFS will ignore ownership information on filesystem objects

     MNT_AUTOMOUNTED        File system was mounted by automounter

     MNT_JOURNALED          File system is journaled

     MNT_DEFWRITE           File system should defer writes

     MNT_MULTILABEL         MAC support for individual labels

CAVEATS
     In Mac OS X versions before 10.4, f_iosize is 4096. On these older systems, use MAXBSIZE instead.

RETURN VALUES
     Upon successful completion, a value of 0 is returned.  Otherwise, -1 is returned and the global vari-able variable
     able 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} characters, or the length of
                        path exceeds {PATH_MAX} 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]           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.

HISTORY
     The statfs() function first appeared in 4.4BSD. The statfs64() and fstatfs64() first appeared in Max OS
     X 10.5 (Leopard).

BSD                            February 11, 1994                           BSD

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