NAME

umount − unmount a file system

SYNOPSIS

int umount (file)
char ∗file;

DESCRIPTION

umount requests that a previously mounted file system contained on the block special device or directory identified by file be unmounted.  file 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 may be invoked only by the super-user. 

umount fails if one or more of the following are true:

­[EPERM] The process’s effective user ID is not super-user. 

­[EINVAL] file does not exist. 

­[ENOTBLK] file is not a block special device. 

­[EINVAL] file is not mounted. 

­[EBUSY] A file on file is busy. 

­[EFAULT] file points to an illegal address. 

­[EREMOTE] file is remote. 

­[ENOLINK] file is on a remote machine, and the link to that machine is no longer active. 

­[EMULTIHOP] Components of the path pointed to by file require hopping to multiple remote machines. 

SEE ALSO

mount(2). 

DIAGNOSTICS

Upon successful completion a value of 0 is returned.  Otherwise, a value of −1 is returned and errno is set to indicate the error. 

September 02, 1992