This was a 100 point miscellaneous problem.
The given program reads 10 bytes off of /dev/urandom
and compares it to your input. The length of the compare is the length of the bytes from urandom.
Since C uses the null byte to determine the end of a string, and urandom will occasionally return that null byte, the actual length of the string is sometimes 1. Simply passing in one character repeatedly will eventually award you the flag.
Command: while true; do ./urandom a; done
Flag: ch!!!zzola