Exercises: Regular expressions

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Pick up a file with some text in it. (e.g. examples/regex-perl/text.txt ). Write a script (one for each item) that prints out every line from the file that matches the requirement. You can use the script at the end of the page as a starting point but you will have to change it!

• has a 'q'
• starts with a 'q'
• has 'th'
• has an 'q' or a 'Q'
• has a '*' in it
• starts with an 'q' or an 'Q'
• has both 'a' and 'e' in it
• has an 'a' and somewhere later an 'e'
• does not have an 'a'
• does not have an 'a' nor 'e'
• has an 'a' but not 'e'
• has at least 2 consecutive vowels (a,e,i,o,u) like in the word "bear"
• has at least 3 vowels
• has at least 6 characters
• has at exactly 6 characters
• all the words with either 'Bar' or 'Baz' in them
• all the rows with either 'apple pie' or 'banana pie' in them
• for each row print if it was apple or banana pie?
• Bonus: Print if the same word appears twice in the same line
• Bonus: has a double character (e.g. 'oo')

examples/regex-perl/regex_exercise.pl

#!/usr/bin/perl
use strict;
use warnings;

my $filename = shift or die "$0 FILENAME\n";
open my $fh, '<', $filename or die "Could not open '$filename'\n";

while (my $line = <$fh>) {
    if ($line =~ /REGEX1/) {
        print "has an a: $line";
    }

    if ($line =~ /REGEX2/) {
        print "starts with an a: $line";
    }
}