First let me say: ROFL! Actually, that really sucks... but its still funny.
md5sum.... mkdir....mv... mknod.... the list goes on.
Start chapter 6 over and reinstall any package that contains a program starting with "m". Remeber there is a pretty good list of programs that are installed at the bottom of every package page in the LFS book.
Then add the following to your ~/.bashrc:
to prevent deleteing files without asking.