I have been interested in completing the coding challenges from this website: https://codingchallenges.fyi/challenges/challenge-wc

In the first challenge, I write a python script to build a wc tool (more info in the link above). The python script, if run in a Unix or Windows environment, will support the command line options: -c (outputs the number of bytes in a file), -l (outputs the number of lines in a file), -w (outputs the number of words in a file), -m (outputs the number of characters in a file), and the default option, which is the equivalent to the -c, -l and -w options.

In grep.py challenge, I built my own version of the Unix command line tool grep. The Unix command line tool grep stands for "global regular expression print". It is used to search text or files for lines that match a specified pattern (regular expression) and print those lines to the standard output. Here are what it does:

• implements support for an empty expression
• matches a simple one letter pattern and return the correct exit code to the shell
• recurses a directory tree, that is to support the command line option -r
• implements the -v option. This inverts the search excluding and result that matches
• supports \d and \w in the search pattern. Their meanings are: \d - a digit. \w - a word character.
• implements support for matching ^ match to the beginning of a line and $ matches to the end.

The challenge is from this website: https://codingchallenges.fyi/challenges/challenge-wc