add shell completion script generation

Cargo.lock

@@ -218,6 +218,15 @@ dependencies = [
  "strsim",
 ]
 
+[[package]]
+name = "clap_complete"
+version = "4.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "885e4d7d5af40bfb99ae6f9433e292feac98d452dcb3ec3d25dfe7552b77da8c"
+dependencies = [
+ "clap",
+]
+
 [[package]]
 name = "clap_derive"
 version = "4.5.0"
@@ -1438,6 +1447,7 @@ dependencies = [
  "chrono",
  "clap",
  "clap-verbosity-flag",
+ "clap_complete",
  "dirs",
  "dunce",
  "env_logger",

Cargo.toml

@@ -11,10 +11,11 @@ license = "MIT OR Apache-1.0"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
-clap = { version = "4.4.0", features = ["derive"] }
+clap = { version = "4.4.0", features = ["cargo", "derive"] }
 sysinfo = { version = "0.29.8", features = ["serde"] }
 log = "0.4"
 clap-verbosity-flag = "2.0.1"
+clap_complete = "4.5.1"
 chrono = { version = "0.4.35", features = ["serde"] }
 env_logger = "0.10.0"
 inquire = "0.6.2"

src/cmd_args.rs

@@ -55,6 +55,11 @@ pub(crate) enum Commands {
 
     /// Check config files.
     Check {},
+
+    /// Generate completion script.
+    Completion {
+        shell: clap_complete::Shell,
+    }
 }
 
 #[derive(Args, Debug)]

src/cmd_completion.rs

@@ -0,0 +1,12 @@
+use crate::cmd_args::Cli;
+use std::io;
+
+use anyhow::Result;
+use clap::CommandFactory;
+use clap_complete::Shell;
+
+pub(crate) fn cmd_completion(shell: Shell) -> Result<()> {
+    let mut cmd = Cli::command();
+    clap_complete::generate(shell, &mut cmd, "xdbm", &mut io::stdout());
+    Ok(())
+}

src/main.rs

@@ -31,6 +31,7 @@ mod cmd_backup;
 mod cmd_init;
 mod cmd_storage;
 mod cmd_sync;
+mod cmd_completion;
 mod devices;
 mod inquire_filepath_completer;
 mod storages;
@@ -122,6 +123,9 @@ fn main() -> Result<()> {
                 } => cmd_backup::cmd_backup_done(name, exit_status, log, repo, &config_dir)?,
             }
         }
+        Commands::Completion { shell } => {
+            cmd_completion::cmd_completion(shell)?
+        }
     }
     full_status(&Repository::open(&config_dir)?)?;
     Ok(())