Write a small shell - called shhh - that has the following capabilities: 1. Can execute a command with the accompanying arguments. 2. Recognize multiple pipe requests and handle them. 3. Recognize redirection requests and handle them. 4. Type "exit" to quit the shhh shell.

3. bob is arguing that if you use output feedback (ofb) mode twice in a row to encrypt a long message, m, using the same key each time, it will be more secure. explain why bob is wrong, no matter what encryption algorithm he is using for block encryption (15 points).

Consider a byte-addressable computer with 16mb of main memory, a cache capable of storing a total of 64kb of data and block size of 32 bytes. (a) how many bits in the memory address? (b) how many blocks are in the cache? (c) specify the format of the memory address, including names and sizes, when the cache is: 1. direct-mapped 2. 4-way set associative 3. fully associative

Which option correctly describes a dbms application? a. software used to manage databases b. software used to organize files and folders c. software used to develop specialized images d. software used to create effective presentations