error on this page
The command linking ~/.bash_history to /dev/null has the arguments in the wrong order. Executing it will overwrite /dev/null, making it non-functional. To remedy the problem, delete /dev/null and re-make the special file with "mknod -m 0666 /dev/null c 1 3".
Use the following command for correct linking: ln -sf /dev/null ~/.bash_history