Files in the directory:

copy.c
empty.c
mystery.c
README
script.sh
strace-identify
tiger.txt
trojaned_cat.c

Directions: 

1. Copy copy.c, empty.c, script.sh, strace-identify, and tiger.txt to a directory 
   that everyone can read

2. Compile mystery.c to an executable named "mystery" and move it to the same 
   directory as in Step 1. Delete mystery.c so students can't find it. 

3. Compile trojaned_cat.c to an executable named "cat" and move it to a directory
   in PATH that comes before /bin (where the "real" /bin/cat lives). 
   Delete trojaned_cat.c so that students can't find it.