NAME

umount − unmount a file system

SYNOPSIS

#include <sys/mount.h>

int umount(const 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 will fail if one or more of the following are true:

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

ENOENT file does not exist. 

ELOOP Too many symbolic links were encountered in translating the path pointed to by file. 

ENAMETOOLONG The length of the file argument exceeds {PATH_MAX}, or the length of a file component exceeds {NAME_MAX} while _POSIX_NO_TRUNC is in effect. 

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ENOLINK file is on a remote machine, and the link to that machine is no longer active.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