NAME
umount — unmount a file system
SYNOPSIS
#include <sys/mount.h>
int umount(const char *name);
DESCRIPTION
umount()
requests that a previously mounted file system
contained on the block special device identified by
name
be unmounted.
name
is a pointer to a path name.
After unmounting the file system, the directory
upon which the file system was mounted
reverts to its ordinary interpretation.
umount()
can also request that a file system mounted
previously on the directory identified by
name
be unmounted.
After unmounting the file system,
name
reverts to its ordinary interpretation.
umount()
can be invoked only by the
user with the appropriate privilege.
NETWORKING FEATURES
NFS
path
must indicate a directory name when unmounting an
NFS
file system.
RETURN VALUE
If successful,
umount()
returns a value of
0.
Otherwise, it returns a value of -1 and sets
errno
to indicate the error.
ERRORS
umount()
fails if one or more of the following are true:
- [EPERM]
The effective user ID of the process
is not that of a
user with appropriate privileges.
- [ENOENT]
name
does not exist.
- [ENOTBLK]
name
is not a block special device.
- [EINVAL]
name
is not mounted.
- [EBUSY]
A file on
name
is busy.
- [EFAULT]
name
points outside the allocated address space of the process.
Reliable detection of this error is implementation dependent.
- [ENXIO]
The device associated with
name
does not exist.
- [ENOTDIR]
A component of
name
is not a directory.
- [ENOENT]
name
is null.
- [ENAMETOOLONG]
name
exceeds
PATH_MAX
bytes, or a component of
name
exceeds
NAME_MAX
bytes while
_POSIX_NO_TRUNC
is in effect.
- [EACCES]
A component of the path prefix of
name
denies search permission.
- [ELOOP]
Too many symbolic links were encountered in translating the path
name.
WARNINGS
If
umount()
is called from the program level (that is, not from the
mount(1M)
level), the table of mounted devices contained in
/etc/mnttab
is not updated automatically.
Updating of
/etc/mnttab
is performed by the
mount
and
syncer
commands (see
mount(1M)
and
syncer(1M)
for more information).
STANDARDS CONFORMANCE
umount(): SVID2, SVID3, XPG2
