Function to validate ham radio callsign

[techpro]

I need a PHP function to return true or false depending on whether the supplied argument is in a valid format for a ham radio callsign. I think this should be possible using regular expressions but I can't figure out how to do it.

 

A valid callsign would be a string containing, starting from the left:

 

- zero or one digits, followed by

- one or two alphabetics, then

- one to four digits, then

- one to three alphabetics.

 

Is this possible?

[phant0m]

That should do the trick:

<?php

function check_call_sign($callsign){
  return preg_match('=\^d?[a-z]{1,2}\d{1,4}[a-z]{1,3}$=i', $callsign);
}
?>

[nrg_alpha]

Phant0m, I think you meant:

 

'=^\d?[a-z]{1,2}\d{1,4}[a-z]{1,3}$=i'

 

Switched the order of \ and ^ at the beginning.

[techpro]

Thanks very much! That seems to work perfectly with all the examples I could think up. Well enough to keep the non-ham would-be spammers from registering anyway. Thanks again.

[phant0m]

Oh yes, of course.

 

Thanks for the correction.

Should have tested it before posting