regex - Delete all lines starting with # or ; in Notepad++

Question

Using Notepad++, how do I remove all lines starting with # or ;?

Answer 1

Find:

^[#;].*

Replace with nothing. The ^ indicates the start of a line, the [#;] is a character class to match either # or ;, and .* matches anything else in the line.

In versions of Notepad++ before 6.0, you won't be able to actually remove the lines due to a limitation in its regex engine; the replacement results in blank lines for each line matched. In other words, this:

# foo
; bar
statement;

Will turn into:

statement;

However, the replacement will work in Notepad++ 6.0 if you add , or to the end of the pattern, depending on which line ending your file is using, resulting in:

statement;