while (<DATA>) {
    chomp;
    my @pieces = grep /[a-z]/i, split /[()]+/;
    printf( "Got %d pieces from '%s' : %s\n",
            scalar @pieces, $_, join( ' and ', @pieces ));
}

__DATA__
(network)(test)(ifcfg)
(network)  (test)_(ifcfg)
(foo).(bar)
(one)(two)--(three)/(four),(five)