#!/usr/bin/env perl -l

use strict;
use warnings;

my $f1 = 'static gboolean g::ber_read(wtap *wth, int *err)';
my $f2 = 'static void ber_set_pkthdr(struct wtap_pkthdr *phdr,
int packet_size)';

for ($f1, $f2) {
    print "Function: $_";
    /([:\w]+\([^)]*\))/m;
    print "Captured: $1";
    # if you want multi-line reduced to single-line:
    (my $no_newlines = $1) =~ y/\n/ /;
    print "Lines joined: $no_newlines";
}