Problem
1. How can you find out whether a program has been executed today?
2. Explain the difference between
(i) ls -l and ls -lt,
(ii) ls -lu and ls -lut.
3. Use find to locate from your home directory tree all
(i) files with the extension .html or .HTML,
(ii) files having the inode number 9076,
(iii) directories having permissions 666,
(iv) files modified yesterday. Will any of these commands fail?