Is it appropriate to handle errors through a subroutine?

smturner1 has asked for the wisdom of the Perl Monks concerning the following question:

Two questions here; one, is it appropriate to place error handling in a subroutine; two, where am I going wrong in the last two 'elsif' statements in this thread?

sub errhand {
    if ($website eq "three"){
    next;
    }
    elsif ($website eq "five"){
    next;
    }
    elsif ($website eq "calnet-test"){
    next;
    }
    #elsif ($old_ip eq /\d\d.\d\d.\d\d\d){
    #next;
    #}
    #elsif ($new_ip eq /\d\d.\d\d.\d\d\d){
    #next;
    #}
    else{
        die, "ERROR - Format is 'deploy website old_ip new_ip || 'depl
+oy [three; five;calnet-test] 21.01.001 22.02.002'"
    }
}
[download]

Comment on Is it appropriate to handle errors through a subroutine? Download Code

Replies are listed 'Best First'.
Re: Is it appropriate to handle errors through a subroutine? by roboticus (Chancellor) on Jan 02, 2014 at 04:27 UTC
smturner1: Putting error handling code in a subroutine is fine, and can help reduce code replication. The last two elsifs aren't matching because $old_ip and $new_ip aren't equal to regular expressions--they're (presumably) strings. If you change the 'eq' into '=~' though, the code will see if the $old_ip and $new_ip match those regular expressions. ;^) ...roboticus When your only tool is a hammer, all problems look like your thumb.	[reply]
Re: Is it appropriate to handle errors through a subroutine? by kcott (Archbishop) on Jan 02, 2014 at 05:39 UTC
G'day smturner1, Here's some additional points beyond those provided by ++roboticus: Your usage of next is inappropriate here as you're not using it to control a looping construct (see "perlsyn: Loop Control"). return is probably what you want (see "perlintro: Writing subroutines"). Both regular expressions have an opening '`/`' but omit a closing one (see "perlretut - Perl regular expressions tutorial"). You use three variables (`$website`, `$old_ip` and `$new_ip`) but haven't declared them. It would probably be better to start your subroutine with: "`my ($website, $old_ip, $new_ip) = @_;`" (again, see "perlintro: Writing subroutines"). There's no comma after die. -- Ken	[reply] [d/l] [select]
Re: Is it appropriate to handle errors through a subroutine? by Anonymous Monk on Jan 02, 2014 at 15:17 UTC
It is clear enough, therefore it will work. Also consider a series of statements (in a subroutine as before) ... `return if ($website eq ...); return if ($new_ip ~= ...); ... die( ...);`	[reply]