Add flag to generate shell completions

Cargo.toml

@@ -18,6 +18,7 @@ async-channel = "1.9.0"
 async-trait = "0.1.73"
 chrono = { version = "0.4.31", features = ["serde"] }
 clap = { version = "4.4.4", features = ["derive"] }
+clap_complete = "4.4.6"
 ctor = "0.2.4"
 ctrlc = "3.4.1"
 indexmap = { version = "2.0.1", features = ["serde"] }

src/main.rs

@@ -1,7 +1,8 @@
 use std::env;
+use std::io;
 use std::time;
 
-use clap::Parser;
+use clap::{CommandFactory, Parser};
 use creds::Credentials;
 
 #[cfg(not(windows))]
@@ -19,12 +20,6 @@ pub(crate) use crate::plugins::Plugin;
 pub(crate) use crate::session::Session;
 
 fn setup() -> Result<Options, session::Error> {
-    print!(
-        "{} v{}\n\n",
-        env!("CARGO_PKG_NAME"),
-        env!("CARGO_PKG_VERSION")
-    );
-
     if env::var_os("RUST_LOG").is_none() {
         // set `RUST_LOG=debug` to see debug logs
         env::set_var("RUST_LOG", "info,blocking=off,pavao=off,fast_socks5=off");
@@ -38,6 +33,11 @@ fn setup() -> Result<Options, session::Error> {
 
     let options: Options = Options::parse();
 
+    if let Some(shell) = options.generate_completions {
+        clap_complete::generate(shell, &mut Options::command(), "legba", &mut io::stdout());
+        std::process::exit(0);
+    }
+
     // list plugins and exit
     if options.list_plugins {
         plugins::manager::list();

src/options.rs

@@ -84,6 +84,11 @@ pub(crate) struct Options {
     #[clap(short = 'Q', long, default_value_t = false)]
     pub quiet: bool,
 
+    /// Generate shell completions
+    #[clap(long)]
+    #[serde(skip)]
+    pub generate_completions: Option<clap_complete::Shell>,
+
     #[clap(flatten, next_help_heading = "COMMAND (CMD)")]
     pub cmd: crate::plugins::cmd::options::Options,
     #[cfg(feature = "amqp")]