Filter lines

The filterLine returns those lines where the closure returns true.

The file test.txt contains the following contents.

Hello World
Hello World 1234
def file = new File("test.txt")
StringWriter writer = new StringWriter()
file.filterLine(writer) { line ->
line.contains("Hello World")
println writer.toString()

This groovy snippets will output the following.

Hello World
Hello World 1234