The scene: you've just run sudo rm -rf --no-preserve-root /.
You're an idiot.
Let's try to recover from this.
echo * LOOK! WE STILL HAVE AN LS, SORT OF! Let's make it better.
printf '%s\n' ${1:+${1%/}/}*
NIIIIIIICE. That's really annoying to type, though.
echo 'ls() { printf '%s\n' ${1:+${1%/}/}*; }' >> utils.sh
. ./utils.sh
Now, ls will act kinda like ls!
type still exists! This will be useful later on, I promise.
What about cat?
(while read line; do echo "$line"; done) < stuff.txt
To find executables: for file in /*; do executable $file; done.
executable () { if [[ ( ! -d $1 ) && ( ! -h $1 ) && -x $1 ]] ; then echo "$1"; fi }
Want to actually lock yourself out of the basically-dead computer?
echo 1 > /proc/sys/kernel/sysrq echo "b" > /proc/sysrq-trigger.
We don't have a text editor anymore, I guess, but we do have
(IFS=$'\n';while read line;do echo "$line";done) < inputfile for reading, and
(IFS=$'\n';while read line;do echo "$line";done) > outputfile for creating a file!
(Ending with the usual Ctrl-D should still work.)
If you're still stuck in a system that you really need to work right now, go to http://eusebeia.dyndns.org/bashcp on some other system and follow through to get yourself BusyBox set up. It will give you everything you need. Also check out http://fakeguido.blogspot.com/2010/08/rescuing-hosed-system-using-only-bash.html for more details on this.