43 lines
1.1 KiB
Rust
43 lines
1.1 KiB
Rust
use std::{env, error::Error, ffi::OsString, process};
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fn run() -> Result<(), Box<dyn Error>> {
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let file_path = get_first_arg()?;
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let mut wtr = csv::Writer::from_path(file_path)?;
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wtr.write_record(&[
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"City",
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"State",
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"Population",
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"Latitude",
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"Longitude",
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])?;
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wtr.write_record(&[
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"Davidsons Landing",
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"AK",
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"",
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"65.2419444",
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"-165.2716667",
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])?;
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wtr.write_record(&["Kenai", "AK", "7610", "60.5544444", "-151.2583333"])?;
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wtr.write_record(&["Oakman", "AL", "", "33.7133333", "-87.3886111"])?;
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wtr.flush()?;
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Ok(())
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}
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/// Returns the first positional argument sent to this process. If there are no
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/// positional arguments, then this returns an error.
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fn get_first_arg() -> Result<OsString, Box<dyn Error>> {
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match env::args_os().nth(1) {
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None => Err(From::from("expected 1 argument, but got none")),
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Some(file_path) => Ok(file_path),
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}
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}
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fn main() {
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if let Err(err) = run() {
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println!("{}", err);
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process::exit(1);
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}
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}
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