NAME
revoke —
revoke file access
LIBRARY
library “libc”
SYNOPSIS
#include
<unistd.h>
int
revoke(const
char *path);
DESCRIPTION
Therevoke()
system call invalidates all current open file descriptors in the system for
the file named by path. Subsequent operations on any
such descriptors fail, with the exceptions that a
read()
from a character device file which has been revoked returns a count of zero
(end of file), and a
close()
system 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 using a special close method which does not block.
Access to a file may be revoked only by its owner or
the super user. The
revoke()
system call is currently supported only for block and character special
device files. It is normally used to prepare a terminal device for a new
login session, preventing any access by a previous user of the terminal.
RETURN VALUES
The revoke() function returns the
value 0 if successful; 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 255 characters, or an entire path name exceeded 1024 characters.
- [
ENOENT] - The named file or a component of the path name does not exist.
- [
EACCES] - Search permission is denied for a component of the path prefix.
- [
ELOOP] - Too many symbolic links were encountered in translating the pathname.
- [
EFAULT] - The path argument points outside the process's allocated address space.
- [
EINVAL] - The implementation does not support the
revoke() operation on the named file. - [
EPERM] - The caller is neither the owner of the file nor the super user.
SEE ALSO
HISTORY
The revoke() system call first appeared in
4.3BSD-Reno.
BUGS
The non-blocking close method is only correctly implemented for terminal devices.