I Screwed Up the System and Can't Log In to Fix It

Reboot from an emergency floppy or floppy pair. For example, the
Slackware boot and root disk pair in the install subdirectory of the
Slackware distribution.

There are also two, do-it-yourself rescue disk creation packages in
ftp://metalab.unc.edu/pub/Linux/system/recovery/. These are better
because they have your own kernel on them, so you don't run the risk
of missing devices and file systems.

Get to a shell prompt and mount your hard disk with something like

$ mount -t ext2 /dev/hda1 /mnt

Then your file system is available under the directory /mnt and you
can fix the problem. Remember to unmount your hard disk before
rebooting (cd somewhere else first, or it will say it's busy).

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