but doesn't seem to be working. What am I doing wrong?

"not working" can mean a lot of things to a lot of people. Please take a look at I know what I mean. Why don't you? or How do I post a question effectively? so we can better understand your issue. Posting code with sample input and expected output is very helpful in diagnosing problems.

Based on what you've posted, I'm guessing the issue you are having is with greedy matching. .* matches as much as it can, whereas .*? grabs the shortest string that meets the criteria. So perhaps the code

($content) = $item1 =~ m/\/(.*?)\?/;

does what you intend? See perlretut for more info.

Also possibly at fault is white space I see in your posted expression. Of course, that might just be an artifact of the fact that you didn't wrap your code in <code> tags; see Writeup Formatting Tips.

Here is another way to do it:

use strict;
use warnings;

my $item1 = 'this is a test /test123?';
my ($content) = $item1 =~ m{ / (.*) \? }x;
print "$content\n" if defined $content;
[download]

• Using alternate delimiters m{} allows you to avoid escaping the slash /
• Using the x modifier allows you to separate the components of your regular expression with whitespace for clarity.
• It is a good practice to check if your match succeeded. I used defined.

Better to test the match result. Consider:

#!/usr/bin/perl
use strict;
use warnings;

for my $str ('Matched', 'No match') {
    $str =~ /(\w*ed)/;
    print "defined: Matched $1 for '$str'\n" if defined $1;
}

for my $str ('Matched', 'No match') {
    print "match: Matched $1 for '$str'\n" if $str =~ /(\w*ed)/;
}
[download]

Prints:

defined: Matched Matched for 'Matched'
defined: Matched Matched for 'No match'
match: Matched Matched for 'Matched'
[download]

True laziness is hard work

this is a test /test123?
$item1 =~ m/ \/(.*) \? /;
[download]

$item1 =~/\/(.*)\?/;
[download]

my $string = 'this is a test /test123?';

my $start = "\Q/\E";
my $end   = "\Q?\E";

my $regexp = qr/$start(.*)$end/;

warn $1 if $string =~ $regexp ;
[download]

my $string = 'this is a test /test123?';

my ($before,$after) = split qr!/!, $string;

chop $after;
warn $after;
[download]