$($In C programming$)$ The uniq program is a common utility available in many Unix installations. This program echoes $($to stdout$)$ its input but will print only a single instance of consecutive matching lines. This is to say that if the input contained the following sequence of lines, then only a single instance of "This is a line." from the first group of matching lines will be printed, followed by "This is a different line.", and then "This is a line." $($though it matches the first three, it was not part of the consecutive sequence$).$

This is a line.

This is a line.

This is a line.

This is a different line.

This is a line.

Write a program $($with main in a file named unique.c$)$ that takes a single $($optional$)$ command$-$line argument specifying a file name. The program must read the contents of the file $($read from stdin if no file is specified$)$ and print the contents of the input stream to stdout such that only a single instance of consecutive matching lines is printed.

Use a single helper function to emulate the uniq functionality.

Note: your program cannot explicitly dynamically allocate memory $($e$.$g$.,$ by using one of the $*$alloc functions$).$ It should use the getline function. A valgrind analysis of your program must not report any issues.