Simulate grep

Write a MyGrep utility based on C. This MyGrep utility is similar to grep utility provided by Unix. Take four features below to finish.

MyGrep utility takes some options, words and text file as arguments.

$MyGrep c This is a list of words test.txt

Count the occurrences of string This is a list of words in the content of file test.txt

$MyGrep c -i This is a listof words test.txt

Count the occurrences of string This is a list of words in the content of file test.txt and ignore cases

$MyGrep o This is a list of words test.txt

Output all lines containing This is a list of words and highlight the matched string

$MyGrep s test.txt

Remove all leading spaces in each line and output the result.

$MyGrep n test.txt

In the output, add a line number at the begging of each line.

$MyGrep n This is a list of words test.txt

Output the lines containing string This is a list of words and add a line number at the begging of each matched line.

$MyGrep k This is a list of words test.txt

Count the occurrences for each word and output the words along with their occurrences in a decreasing order.

For example, the output could be

a 20

is 8

list 5

words 3

of 2

this 1