No-no-no, why do you think it should not fail?
And hint: you can use different separators instead of slashes - s/find/replace/ can be s|find|replace, for example.
(my $file_name) = $line =~ /
\/ #match a front slash "/"
[^\/]#dont match any more frontslashes
(.*)#match everything after / and save
\s-\s#match a " - "
/;