Perl seems to be an amazingly succint way of writing programs, but I seem to be having a nightmare debugging this simple script! 
#!/usr/bin/perl
#testargscan.pl - a script for testing
use warnings;
sub argscan{ 
if ($#ARGV == 1) {return (0)}
else {
    my @subarg = (qw($_[0] $_[1] $_[2]));
    my $argcount = 0;
    my $found;
    my $notfound;
    my @whenfound;
    while ($argcount <= $#ARGV) {
        if ($subarg[0] = undef) {
            $argcount = $#ARGV;
            return $argcount
        }
        if ($ARGV[$argcount] == $subarg[0]){
            $found++;
            $whenfound[$argcount] = 1;
        }
    
     else {
        $notfound++;
        $whenfound[$argcount] = 0;
        #goto (proper)
    }

unless ($argcount == $#ARGV) {
    $argcount++
}
}
}


if ($subarg[1] eq 'foundcount') {
    unless ($found == undef) {
        return $found}
    else {return 0}
}
elsif ($subarg[1] eq 'argcount'){
     unless ($argcount == undef) {
        return $argcount}
    else {return 0}
}
elsif ($subarg[1] eq 'notfoundcount') {
    unless ($notfound == undef) {
        return $notfound}
    else {return 0}
}
elsif ($subarg[1] eq 'hunt') {
unless ($found == undef) {
        return $whenfound[$subarg[2]]}
    else {return 0}
}
else {return 0};
}

$argnumber = argscan(undef);
$carnumber = argscan(qw (car foundcount));
$notcarnumber = argscan(qw(car notfoundcount));
$bunnynumber = argscan(qw(bunny foundcount));



print "there are $argnumber arguments \n
    there are $carnumber cars 
    there are $bunnynumber bunnies 
    $notcarnumber args are not cars \n ";

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it's probably a pretty shoddy piece of code, I keep on getting very odd error messages such as:

"Name "main::whenfound" used only once: possible typo at testargscan.pl line 54."

when that isn't true, and sometimes the perl interpreter just freezes
If someone will tell me what i'm missing I can go though the process of feeling stupid for not realising it and then learning from my mistake
PS: It can work, but all the final values will be 0

2006-08-09 Retitled by Corion, as per Monastery guidelines
Original title: 'Confused'

In reply to Confused about 'Name "main::whenfound" used only once:' by Maze

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