NAME
statfs, fstatfs
— get file system
statistics
LIBRARY
library “libc”
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 filesystem.
Buf is a pointer to a
statfs()
structure defined as follows:
typedef struct fsid { int32_t val[2]; } fsid_t; /* file system id type */
/*
* file system statistics
*/
#define MFSNAMELEN 16 /* length of fs type name, including null */
#define MNAMELEN 90 /* length of buffer for returned name */
struct statfs {
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 filesystem */
int f_type; /* type of filesystem */
int f_flags; /* copy of mount exported flags */
long f_syncwrites; /* count of sync writes since mount */
long f_asyncwrites; /* count of async writes since mount */
char f_fstypename[MFSNAMELEN]; /* fs type name */
char f_mntonname[MNAMELEN]; /* directory on which mounted */
long f_syncreads; /* count of sync reads since mount */
long f_asyncreads; /* count of async reads since mount */
char f_mntfromname[MNAMELEN];/* mounted filesystem */
};
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_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.
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.
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
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 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] - 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
HISTORY
The statfs() function first appeared in
4.4BSD.