Simple grep like file search

Used for educational purposes

Implements the following functions

Usage: ./fs [options] pattern files... Options: -i Ignore case when searching -r Show lines that do NOT match -n Show line numbers -f Show file basename on each line -F Show file name as section title -m Only show file names that have a match -c Print only a count of matching lines -v Print fs version information -b Print N lines before a match (e.g. -b2) -a Print N lines after a match (e.g. -a3) -l Print only the first n chars of each line (e.g. -l20) -L Crop the first n chars of each line (e.g. -L5)