keyfork: add completion generator

Cargo.lock

@@ -630,6 +630,15 @@ dependencies = [
  "terminal_size",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "4.4.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "97aeaa95557bd02f23fbb662f981670c3d20c5a26e69f7354b28f57092437fcd"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "4.4.7"
@@ -1522,6 +1531,7 @@ version = "0.1.0"
 dependencies = [
  "card-backend-pcsc",
  "clap",
+ "clap_complete",
  "keyfork-derive-openpgp",
  "keyfork-derive-util",
  "keyfork-entropy",

keyfork/Cargo.toml

@@ -4,6 +4,10 @@ version = "0.1.0"
 edition = "2021"
 license = "AGPL-3.0-only"
 
+[features]
+default = ["completion"]
+completion = ["dep:clap_complete"]
+
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
@@ -23,3 +27,4 @@ openpgp-card-sequoia = "0.2.0"
 openpgp-card = "0.4.1"
 keyfork-prompt = { version = "0.1.0", path = "../keyfork-prompt" }
 keyfork-entropy = { version = "0.1.0", path = "../keyfork-entropy" }
+clap_complete = { version = "4.4.6", optional = true }

keyfork/src/cli/mod.rs

@@ -1,4 +1,4 @@
-use clap::{Parser, Subcommand};
+use clap::{CommandFactory, Parser, Subcommand};
 
 mod derive;
 mod mnemonic;
@@ -37,6 +37,13 @@ pub enum KeyforkCommands {
 
     /// Utilities to automatically manage the setup of Keyfork.
     Wizard(wizard::Wizard),
+
+    /// Print an autocompletion file to standard output.
+    #[cfg(feature = "completion")]
+    Completion {
+        #[arg(value_enum)]
+        shell: clap_complete::Shell,
+    },
 }
 
 impl KeyforkCommands {
@@ -61,6 +68,17 @@ impl KeyforkCommands {
             KeyforkCommands::Wizard(w) => {
                 w.handle(keyfork)?;
             }
+            #[cfg(feature = "completion")]
+            KeyforkCommands::Completion { shell } => {
+                let mut command = Keyfork::command();
+                let command_name = command.get_name().to_string();
+                clap_complete::generate(
+                    *shell,
+                    &mut command,
+                    command_name,
+                    &mut std::io::stdout(),
+                );
+            }
         }
         Ok(())
     }