$ chmod 777 parse.sh
$ ./parse.sh
Lexer file - Returns tokens to parser when input text matches.
Prints invalid character if text not matched.
Ignores comments, whitespaces and newlines.
Parser - Returns whether input was parsed successfully (valid) or not.
Contains the grammar for valid PHP code.
Prints errors along with line number on invalid input.
Lexer file - Prodcues a copy of the input php file without comments