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29 lines
660 B
Rust
29 lines
660 B
Rust
//! Counts the number of lines in a file given as an argument.
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#![feature(async_await)]
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use std::env::args;
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use async_std::fs::File;
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use async_std::io::{self, BufReader};
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use async_std::prelude::*;
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use async_std::task;
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fn main() -> io::Result<()> {
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let path = args().nth(1).expect("missing path argument");
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task::block_on(async {
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let file = BufReader::new(File::open(&path).await?);
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let mut lines = file.lines();
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let mut count = 0u64;
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while let Some(line) = lines.next().await {
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line?;
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count += 1;
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}
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println!("The file contains {} lines.", count);
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Ok(())
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})
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}
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