Function pipe_through_command 

pub fn pipe_through_command<I, S>(
    cmd: &str,
    args: I,
    input: &str,
    cwd: &Path,
    bufid: usize,
) -> Result<String>
where
    I: IntoIterator<Item = S>,
    S: AsRef<OsStr>,

Pipe input text through an external command, returning the output