38 lines
1.1 KiB
Rust
38 lines
1.1 KiB
Rust
use std::{env, error::Error, io, process};
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fn run() -> Result<(), Box<dyn Error>> {
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// Get the query from the positional arguments.
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// If one doesn't exist, return an error.
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let query = match env::args().nth(1) {
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None => return Err(From::from("expected 1 argument, but got none")),
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Some(query) => query,
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};
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// Build CSV readers and writers to stdin and stdout, respectively.
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let mut rdr = csv::Reader::from_reader(io::stdin());
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let mut wtr = csv::Writer::from_writer(io::stdout());
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// Before reading our data records, we should write the header record.
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wtr.write_record(rdr.headers()?)?;
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// Iterate over all the records in `rdr`, and write only records containing
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// `query` to `wtr`.
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for result in rdr.records() {
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let record = result?;
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if record.iter().any(|field| field == &query) {
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wtr.write_record(&record)?;
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}
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}
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// CSV writers use an internal buffer, so we should always flush when done.
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wtr.flush()?;
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Ok(())
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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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