C[10] is initialized as all elements having a value of 0.
- make pointer p point to array a;
- use pointer p to update the value of a[4] to be 5.

commands
- create a symbolic link called a. txt to file b. txt in a given directory.
- create a compressed tar archive for the contents of a given directory path.
- print all lines in a file or a set of files starting with string "user".
- add execute permission to a given file.
- use ls command with some of its options to achieve specific listing.