clap-digest

Integration to choose digest with clap on a CLI.

Features

1. A clap::ValueEnum implementation for the different digest algorithm types:

   rust let algorithm = Arg::with_name("algorithm") .short('a') .long("algorithm") .help("digest algorithm") .takes_value(true) // this here is the important bit: .value_parser(clap::builder::EnumValueParser::<Digest>::new());

2. A conversion from clap_digest::Digest to digest::DynDigest:

   ```rust // fn doing some hashing, using any DynDigest implementation fn dynhash(hasher: &mut dyn DynDigest, data: &[u8]) -> String { hasher.update(data); let hash = hasher.finalizereset(); hash.iter().map(|byte| format!("{:02x}", byte)).collect() }

   // parse user-supplied CLI input to clapdigest::Digest with clap // suppose user runs this with: command --algorithm MD5 // let args = cli.getmatches(); let digest = *args.get_one::("algorithm").unwrap();

   // convert to DynDigest let mut digest: Box = digest.into();

   // use with hashing function let hash = dyn_hash(&mut (*digest), b"foo");

   assert_eq!(hash, "acbd18db4cc2f85cedef654fccc4a4d8"); ```

3. Algorithm groups are feature-gated (see example below). Use cargo feature clap-digest for a complete listing.

Example

For a complete CLI example, see examples/cksum.rs.

```console $ cargo run --example cksum -- -a SHA1 Cargo.toml 7a96ee85606435fe1f39c3fa6bdf4cf9bbbc338c Cargo.toml

$ sha1sum Cargo.toml 7a96ee85606435fe1f39c3fa6bdf4cf9bbbc338c Cargo.toml

$ cargo run --example cksum -- -a MD5 Cargo.toml | md5sum -c Cargo.toml: OK ```

List all supported algorithms:

console $ cargo run --example cksum -- --list-algorithms BLAKE2b512 BLAKE2s256 BLAKE3 ...

All algorithm groups are feature-gated, so you can choose:

console $ cargo run --example cksum --no-default-features --features md5,sha1,sha2 -- --list-algorithms MD5 SHA1 SHA224 SHA256 SHA384 SHA512 SHA512/224 SHA512/256