cli_app/
lib.rs

1pub fn match_pattern(
2    pattern: &str,
3    content: &str,
4    mut output: impl std::io::Write,
5) -> Result<(), std::io::Error> {
6    for (counter, line) in content.lines().enumerate() {
7        if line.contains(&pattern) {
8            writeln!(&mut output, "{:},{:}", counter, line)?
9        }
10    }
11    Ok(())
12}