Crate nix_nar

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Summary

Library to manipulate Nix Archive (nar) files.

For the NAR specification, see “The Purely Functional Deployment Model” by Eelco Dolstra, Figure 5.2 (page 93).

Encoding

To encode a directory as a NAR file, first create an Encoder with Encoder::new, then treat it as a std::io::Read instance. For instance, you can std::io::copy it to a file.

use nix_nar::Encoder;
let mut enc = Encoder::new("some/dir").unwrap();
let mut nar = File::create("output.nar")?;
io::copy(&mut enc, &mut nar)?;

If you have very long filenames, use Encoder::builder() and then configure the internal buffer size to be at least 200 bytes larger than the longest filename.

Alternatively, use the Encoder::pack helper.

Decoding

To decode a NAR file, first create a Decoder with Decoder::new, and then call Decoder::entries to iterate through the files in the archive.

  use nix_nar::Decoder;
  let input = include_bytes!("../test-data/02-empty-file.nar");
  let dec = Decoder::new(&input[..])?;
  for entry in dec.entries()? {
    let entry = entry?;
    println!("{:?} {:?}", entry.path, entry.content);
  }

Alternatively, use Decoder::unpack to extract a NAR file to a directory.

Modules

  • debug
    Debugging utilities.

Structs

Enums