1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27

//! Counts the number of records in a GTF file.
//!
//! The result matches the output of `grep --count --invert-match "^#" <src>`.

use std::{
    env,
    fs::File,
    io::{self, BufReader},
};

use noodles_gtf as gtf;

fn main() -> io::Result<()> {
    let src = env::args().nth(1).expect("missing src");

    let mut reader = File::open(src).map(BufReader::new).map(gtf::Reader::new)?;
    let mut n = 0;

    for result in reader.records() {
        let _ = result?;
        n += 1;
    }

    println!("{n}");

    Ok(())
}