Perl Regex not matching
===

I'm trying to match lines from a file and extract a certain part.
My Regex works with all online testers I could find but not with my perl.
I'm on version v5.10.0 and cannot update.

The regex looks like this:

      if ($_[0] =~ m/^copy\s+.*?\s+(.*?\_.*?)$/) {
                 return $1;
      }

A couple of lines of test data which should match (only the last matches):

    copy xxxxxx_/cpu     b_relCAP_R3.0-1_INT5_xxxxx_cpu_p1
    copy xxxxxxxx_/va_xxx_parameters    b_relCAP_R3.0-1_INT5_xxxxx_va_xxx_parameters_p1
    copy xxxxxxxx_/xxxxxxx_view.tcl      b_relCAP_R3.0-1_INT5_xxxxxx_view.tcl_p0
    copy xxxxx_/xxxxxarchivetool.jar   b_relEARLY_DROP1_xxxxxarchivetool.jar_xx