build: generate completion scripts

Cargo.toml

@@ -14,3 +14,7 @@ categories = ["rust", "cli", "compression", "command-line", "tool"]
 
 [dependencies]
 clap = { version = "4.5.4", features = ["derive"] }
+
+[build-dependencies]
+clap = { version = "4.5.4", features = ["derive"] }
+clap_complete = "4.5.2"

build.rs

@@ -0,0 +1,33 @@
+use clap::{Command, CommandFactory};
+use clap_complete::Shell;
+use std::fs::File;
+use std::path::Path;
+
+include!("src/cli.rs");
+const APP_NAME: &str = "unicom";
+
+fn generate(s: Shell, app: &mut Command, outdir: &Path, file: &str) {
+    let destfile = outdir.join(file);
+    println!("dest: {}", destfile.display());
+
+    std::fs::create_dir_all(destfile.parent().unwrap()).unwrap();
+    let mut dest = File::create(destfile).unwrap();
+    clap_complete::generate(s, app, APP_NAME, &mut dest);
+}
+
+fn main() {
+    let mut app = Args::command();
+    app.set_bin_name(APP_NAME);
+
+    let outdir = Path::new(env!("CARGO_MANIFEST_DIR")).join("target/completions/");
+    generate(Shell::Bash, &mut app, &outdir, "unicom-completion.bash");
+    generate(Shell::Zsh, &mut app, &outdir, "_unicom");
+    generate(Shell::Fish, &mut app, &outdir, "unicom-completion.fish");
+    generate(
+        Shell::PowerShell,
+        &mut app,
+        &outdir,
+        "unicom-completion.ps1",
+    );
+    generate(Shell::Elvish, &mut app, &outdir, "unicom-completion.elv");
+}