[SHELL-FU] How good are you?

Let's say you have access to a system where there are NO core utilities (atleast no cat, ls, you know, the basic stuff), due to a REALLY restricted shell, or even rm -rf /

Do you just cry yourself to bed?

Here's some cool stuff:

Same as cat file.txt

 $ while read line; do echo $line; done < file.txt 

Same as grep whatever file.txt

 $ while read line; do if [[ $line == *whatever* ]]; then echo $line; fi; done < file.txt 

Same as wc -l file.txt

 $ i=0; while read line; do i=$((i+1)); done < file.txt; echo $i 

"Same" as ls /bin

 $ echo /bin/* 

"Same" as uname -a

 $ while read line; do echo $line; done < /proc/version 

Same as id

 $ echo uid=$UID gid=nobody fucking cares 

"Same" as ps

 $ for i in /proc/*; do if [ -f $i/comm ]; then while read line; do echo $line; done < $i/comm; fi; done 

Same as ldd /bin/ls

 $ LD_TRACE_LOADED_OBJECTS=1 /bin/ls 

And the list goes on.

What can you come up with in these non-confy situations?