For example, I want to remove unwanted line with bbbb

```
aaaa
bbbb
cccc
dddd

```

I use the following perl regular expression to accomplish this.

```
$_ =~ s/bbbb//g;

```

The problem here is that a blank line is stays, for example

```
aaaa

cccc
dddd

```

I need to remove the unwanted text line and also the blank line.