Add shell completion subcommand

fclones/Cargo.toml

@@ -24,6 +24,7 @@ bytesize = "1.1"
 byte-unit = "4.0"
 chrono = { version = "0.4", default-features = false, features = ["serde", "clock", "std"] }
 clap = { version = "4.4", features = ["derive", "cargo", "wrap_help"] }
+clap_complete = { version = "4.5.36" }
 console = "0.15"
 crossbeam-channel = "0.5"
 crossbeam-utils = "0.8"

fclones/src/config.rs

@@ -729,6 +729,12 @@ pub enum Command {
         #[arg()]
         target: PathBuf,
     },
+
+    /// Print shell completion script to stdout.
+    Complete {
+        /// Shell for which the completion script is generated.
+        shell: clap_complete::aot::Shell,
+    },
 }
 
 impl Command {

fclones/src/main.rs

@@ -6,7 +6,7 @@ use std::process::exit;
 use std::sync::Arc;
 use std::{fs, io};
 
-use clap::Parser;
+use clap::{CommandFactory, Parser};
 use console::style;
 use fallible_iterator::FallibleIterator;
 use itertools::Itertools;
@@ -283,6 +283,17 @@ fn main() {
             let target = Arc::new(fclones::Path::from(cwd)).resolve(target);
             run_dedupe(DedupeOp::Move(Arc::new(target)), config, &log)
         }
+        Command::Complete { shell } => {
+            clap_complete::generate(
+                shell,
+                &mut Config::command(),
+                std::env::args()
+                    .next()
+                    .unwrap_or_else(|| "fclones".to_owned()),
+                &mut std::io::stdout(),
+            );
+            Ok(())
+        }
     };
 
     if let Err(e) = result {