sub common_suffix {
my $comm = shift @_;
while ($_ = shift @_) {
$_ = substr($_,-length($comm))
if (length($_) > length($comm));
$comm = substr($comm,-length($_))
if (length($_) < length($comm));
if (( $_ ^ $comm ) =~ /(\0*)$/) {
$comm = substr($comm, -length($1));
} else {
return undef;
}
}
return $comm;
}
sub common_prefix {
my $comm = shift @_;
while ($_ = shift @_) {
$_ = substr($_,0,length($comm))
if (length($_) > length($comm));
$comm = substr($comm,0,length($_))
if (length($_) < length($comm));
if (( $_ ^ $comm ) =~ /^(\0*)/) {
$comm = substr($comm,0,length($1));
} else {
return undef;
}
}
return $comm;
}