feat: introduce new OmniBOR CLI.

omnibor/Cargo.toml

@@ -14,7 +14,18 @@ version = "0.3.0"
 gitoid = "0.5.0"
 tokio = { version = "1.36.0", features = ["io-util"] }
 url = "2.5.0"
+clap = { version = "4.5.1", features = ["derive"], optional = true }
+anyhow = { version = "1.0.80", optional = true }
 
 [dev-dependencies]
 tokio = { version = "1.36.0", features = ["io-util", "fs"] }
 tokio-test = "0.4.3"
+
+[features]
+build-binary = ["anyhow", "clap"]
+
+[[bin]]
+name = "omnibor"
+test = false
+bench = false
+required-features = ["build-binary"]

omnibor/src/bin/omnibor.rs

@@ -0,0 +1,67 @@
+use anyhow::Context as _;
+use anyhow::Result;
+use clap::Args;
+use clap::Parser;
+use clap::Subcommand;
+use omnibor::Sha256;
+use std::fs::File;
+use std::path::PathBuf;
+use std::process::ExitCode;
+
+fn main() -> ExitCode {
+    let args = Cli::parse();
+
+    let result = match args.command {
+        Command::Id(args) => run_id(args),
+    };
+
+    if let Err(err) = result {
+        eprintln!("{}", err);
+        return ExitCode::FAILURE;
+    }
+
+    ExitCode::SUCCESS
+}
+
+
+/*===========================================================================
+ * CLI Arguments
+ *-------------------------------------------------------------------------*/
+
+#[derive(Debug, Parser)]
+#[command(version)]
+struct Cli {
+    #[command(subcommand)]
+    command: Command,
+}
+
+#[derive(Debug, Subcommand)]
+enum Command {
+    /// Print the Artifact ID of the path given.
+    Id(IdArgs),
+}
+
+#[derive(Debug, Args)]
+struct IdArgs {
+    /// The path to identify.
+    path: PathBuf,
+}
+
+
+/*===========================================================================
+ * Command Implementations
+ *-------------------------------------------------------------------------*/
+
+/// Type alias for the specific ID we're using.
+type ArtifactId = omnibor::ArtifactId<Sha256>;
+
+/// Run the `id` subcommand.
+///
+/// This command just produces the `gitoid` URL for the given file.
+fn run_id(args: IdArgs) -> Result<()> {
+    let path = &args.path;
+    let file = File::open(path).with_context(|| format!("failed to open '{}'", path.display()))?;
+    let id = ArtifactId::id_reader(&file).context("failed to produce Artifact ID")?;
+    println!("{}", id.url());
+    Ok(())
+}