umount(3)umount(3)NAMEumount - Unmount a file system
char *spec );
System V Compatibility Library (libsys5.a)
Points to the pathname of the special file or file system to be
The umount() function unmounts a previously-mounted file system con‐
tained on the block special file pointed to by the spec parameter. When
the file system is unmounted, the directory mount point where the file
system was mounted returns to its normal interpretation.
The umount() function can only be invoked by the superuser.
Two umount() functions are supported by the Tru64 UNIX operating sys‐
tem: the BSD umount() and the System V umount(). The default umount()
function is the BSD umount() . To use the version of umount() docu‐
mented on this reference page, you must link with the libsys5 library
before you link with libc.
If the umount() function fails, errno may be set to one of the follow‐
ing values: The effective user ID of the calling process is not root.
The spec parameter points to a pathname that does not exist. A compo‐
nent of the path prefix of spec is not a directory. The device identi‐
fied by spec is not a block-special device. The device identified by
spec does not exist. A file on the device pointed to by the spec
parameter is busy. The device pointed to by the spec parameter is not
The umount() function returns 0 (zero) if the file system was success‐
fully unmounted. Otherwise, -1 is returned and errno is set to indicate