statfs, fstatfs - get file system statistics
Standard C Library (libc, -lc)
#include <sys/param.h>
#include <sys/mount.h>
int
statfs(const char *path, struct statfs *buf);
int
fstatfs(int fd, struct statfs *buf);
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; /* file system id type */
#define MFSNAMELEN 16 /* length of fs type name, including nul */
#define MNAMELEN 90 /* length of buffer for returned name */
struct statfs {
short f_type; /* type of file system (unused; zero) */
u_short f_oflags; /* deprecated copy of mount flags */
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 */
long f_flags; /* copy of mount flags */
long f_syncwrites; /* count of sync writes since mount */
long f_asyncwrites; /* count of async writes since mount */
long f_spare[1]; /* 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 */
};
The flags that may be returned include:
MNT_RDONLY The filesystem is mounted read-only; Even the super-user
may not write on it.
MNT_NOEXEC Files may not be executed from the filesystem.
MNT_NOSUID Setuid and setgid bits on files are not honored when
they are executed.
MNT_NODEV Special files in the filesystem may not be opened.
MNT_SYNCHRONOUS All I/O to the filesystem is done synchronously.
MNT_ASYNC No filesystem I/O is done synchronously.
MNT_UNION Union with underlying filesystem.
MNT_NOCOREDUMP Don't write core dumps to this file system.
MNT_NOATIME Never update access times.
MNT_SYMPERM Recognize symbolic link permission.
MNT_NODEVMTIME Never update mod. times for device files.
MNT_SOFTDEP Use soft dependencies.
MNT_LOCAL The filesystem resides locally.
MNT_QUOTA The filesystem has quotas enabled on it.
MNT_ROOTFS Identifies the root filesystem.
MNT_EXRDONLY The filesystem is exported read-only.
MNT_EXPORTED The filesystem is exported for both reading and writing.
MNT_DEFEXPORTED The filesystem is exported for both reading and writing
to any Internet host.
MNT_EXPORTANON The filesystem maps all remote accesses to the anonymous
user.
MNT_EXKERB The filesystem is exported with Kerberos uid mapping.
MNT_EXNORESPORT Don't enforce reserved ports (NFS).
MNT_EXPUBLIC Public export (WebNFS).
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.
Upon successful completion, a value of 0 is returned. Otherwise, -1 is
returned and the global variable errno is set to indicate the error.
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.
The statfs() function first appeared in 4.4BSD.
BSD May 24, 1995 BSD
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