echocommand to write to this file, a remote root user can execute most System Request Key commands remotely as if at the local terminal. To
echovalues to this file, the
/proc/sys/kernel/sysrqmust be set to a value other than
0. For more information about the System Request Key, refer to Section 188.8.131.52, “
Although it is possible to write to this file, it cannot be read, even by the root user.