REVOKE(2) | System Calls Manual | REVOKE(2)

# 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 Subsequent operations on any such descriptors fail, with the exceptions that a `read`() from a tty which has been revoked returns a count of zero (end of file), and a `close`() call will succeed.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.

June 30, 2021 | Debian