Task — Valid phone numbers

You are given a text file. Write a script to display all valid phone numbers in the given text file.

Valid phone numbers have one of 3 possible formats:

• +nn nnnnnnnnnn
• (nn) nnnnnnnnnn
• nnnn nnnnnnnnnn

Examples

Input:
0044 1148820341
 +44 1148820341
  44-11-4882-0341
(44) 1148820341
  00 1148820341
Output:
 0044 1148820341
 +44 1148820341
(44) 1148820341

Analysis

This is just a case of matching against 3 regexes. I allowed leading and trailing spaces, and more than one space where the allowed format has a single space, but output the numbers left justified and with single spaces where allowed.

Having coded this in real life I know that the range of valid UK phone numbers is somewhat larger than stated, and the number of formats encountered in a database where the field accepted any number of any characters is vastly larger.

Try it 

#!/usr/bin/perl

# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge

use v5.26;    # The Weekly Challenge - 2021-04-26
use utf8;     # Week 110 - task 1 - Valid phone numbers
use warnings; # Peter Campbell Smith
binmode STDOUT, ':utf8';
use Encode;

valid_phone_numbers();

sub valid_phone_numbers {
    
    my ($phone);
    
    # initialise
    $phone = <DATA>;
    chomp $phone;
    say $phone;
    
    # check for valid format
    while ($phone = <DATA>) {
        say $1 if ($phone =~ m|^\s*(\+\d\d\s+\d+)\s*$|
                or $phone =~ m|^\s*(\(\d\d\)\s+\d+)\s*$|
                or $phone =~ m|^\s*(00\d\d\s+\d+)\s*$|);
    }
}

__DATA__
0044 1148820341
 +44 1148820341
  44-11-4882-0341
(44) 1148820341
  00 1148820341
  

15 lines of code

I completed this challenge after the closing date
and it has not been submitted to GitHub

Output

Input:
0044 1148820341
+44 1148820341
44-11-4882-0341
(44) 1148820341
00 1148820341

Output:
0044 1148820341
+44 1148820341
(44) 1148820341