implement basic shell functionality: <, >, |.
treeb51cf934dc8224ac2bab186a6fb241eefc4991d2
-rw-r--r-- 33349 .bochsrc
-rw-r--r-- 1115 CODING
-rw-r--r-- 4637 GNUmakefile
drwxr-xr-x - boot
drwxr-xr-x - conf
drwxr-xr-x - fs
-rw-r--r-- 4446 grade.sh
drwxr-xr-x - inc
drwxr-xr-x - kern
drwxr-xr-x - lib
-rw-r--r-- 2331 mergedep.pl
drwxr-xr-x - user