Select file by filenamepattern

Question

In my directory I've following filename pattern:

1. Pattern
2018_09_01_Filename.java

or

2. Pattern
kit-deploy-190718_Filename.java

Now I'm trying to select every file in the directory which is matching with the first pattern (the date can be different but it's always year_month_day). But I don't get any further.

I've been thinking that I could split the basename from the file so that I get the first ten characters. Then I'll look if this is matching with a pattern.

my $filename = basename($file);

my $chars = substr($filename, 0 , 10);

if ($chars =~ m/2000_01_01/) {

    print "match\n";

}
else {
    print "Don't match";
}

---

Answer 1

You just need a regex that matches your needs, example:

#!/usr/bin/perl

my $filename = "2018_09_01_Filename.java";


if ($filename =~ m/\D?20\d{2}_\d{2}_\d{2}\D?/) {
    print "match\n";
}

Explanation

• \D? matches any character that's not a digit

  • ? Quantifier — Matches between zero and one times, as many times as possible, giving back as needed (greedy)

• 20 matches the characters 20 literally (case sensitive)

• \d{2} matches a digit

  • {2} Quantifier — Matches exactly 2 times

• _ matches the character _ literally

• \d{2} matches a digit

  • {2} Quantifier — Matches exactly 2 times

• _ matches the character _ literally

• \d{2} matches a digit

  • {2} Quantifier — Matches exactly 2 times

• \D? matches any character that's not a digit

  • ? Quantifier — Matches between zero and one times, as many times as possible, giving back as needed (greedy)

Check the demo