Problem
1. Write two programs that read /etc/passwd using
(i) a single-character buffer,
(ii) a buffer of 2048 bytes with read. Use the time command with each and compare their performance.
2. Write a program that displays the current value of the user mask but leaves it unchanged.
3. Using access, devise an advisory locking mechanism which allows two programs, lock1.c and lock2.c, to read a file foo only if the file .lockfile doesn't exist. Both programs will first create the lock file if it doesn't exist and then will remove it before termination.