NAME

revoke — revoke file access

SYNOPSIS

#include <unistd.h>

int
revoke(const char *path);

DESCRIPTION

The revoke() function invalidates all current open file descriptors in the system for the tty device named by path. Subsequent operations on any such descriptors fail, with the exceptions that a read() from a tty which has been revoked returns a count of zero (end of file), and a close() call will succeed. If the file is a special file for a device which is open, the device close function is called as if all open references to the file had been closed.

Access to a file may be revoked only by its owner or the superuser. The revoke() function is used to prepare a terminal device for a new login session, preventing any access by a previous user of the terminal. The pty(4) subsystem has this as an implicit operation, but hardwired tty(4) require the operation.

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

Access to the named file is revoked unless one of the following:

[ENOTDIR]

A component of the path prefix is not a directory.

[ENAMETOOLONG]

A component of a pathname exceeded NAME_MAX characters, or an entire pathname (including the terminating NUL) exceeded PATH_MAX bytes.

[ENOENT]

The named file or a component of the pathname does not exist.

[ENOTTY]

path is not associated with a tty special device.

[EACCES]

Search permission is denied for a component of the path prefix.

[ELOOP]

Too many symbolic links were encountered in translating the pathname.

[EFAULT]

path points outside the process's allocated address space.

[EPERM]

The caller is neither the owner of the file nor the superuser.

SEE ALSO

close(2)

HISTORY

The revoke() function was introduced in 4.3BSD-Reno.