Compare a current user against a list of employees logged into computers Perl, CGI - html

Question

Not sure I am doing this correctly as it doesn't appear to be working.
Is this the correct way to declare my users, and is the If statement correctly formated?
At the top I have declared:
my $las = 'jpietrza hpietrza oszones';
These are employees we are checking against current users.
Further down in the code, I want to change the text color that is printed if the user is in the list vs. someone else.
while ( $sth->fetch() ) {
next unless defined $currentuser;
$lastlogin =~ s/ .*$//;
$host_name =~ s/1408//;
foreach ( #las ) {
if ( $currentuser eq "$_" ) {
$lacolor = "black";
last;
}
else {
$lacolor = "red";
}
}
print "<tr>";
print "<td>$host_name</td>";
print "<td><font color=\"$lacolor\">System In-Use (User Undisclosed)</font></td><td> </td>";
}

Answer 1

maybe there was nothing wrong with the if statement, but the whole 9 lines of code can be condensed to 1 very readable line:
$lacolor = any { /^$currentuser$/ } #las ? "black" : "red";
please
use List::Util qw/any/;
while($sth->fetch()) {
# $currentuser is assigned between the 'while' and this 'next' statement ?
# if not, then outside the loop and do not loop at all unless defined
next unless defined $currentuser;
$lastlogin=~s/ .*$//;
$host_name=~s/1408//;
$lacolor = any { /^$currentuser$/ } #las ? "black" : "red";
print "<tr>";
print "<td>$host_name</td>";
print "<td><font color=\"$lacolor\">System In-Use (User Undisclosed)</font></td><td> </td>";
}
please, also use strict; and use warnings;

Answer 2

I figured out how to put the array together correctly:
my #las = qw(
jpietrza
hpietrza
oszones
);
instead of:
my $las='
jpietrza
hpietrza
oszones
';

Answer 3

Firstly, as I think you have worked out now, the scalar variable $las and the array #las are completely different. As you've seen, you should declare and initialise your array like this:
my #las = qw(
jpietrza
hpietrza
oszones
);
Actually, I suspect this all gets easier if you store this in a hash, not an array;
my %las = map { $_ => 1 } qw(jpietrza hpietrza oszones);
Then your check just becomes:
my $lacolour = $las{$currentuser} ? 'black' : 'red';
A few more points:
Please add use strict and use warnings. And understand and fix the problems they reveal.
The quotes are unnecessary in if ($currentuser eq "$_").
Using a templating system to create the output will make your life a lot easier.
Update: Oh, and one I forgot earlier. It's 2017. No-one has used the font element in HTML for fifteen years. Take a look at CSS.