Add shell completion and manpage generation (#233)

src/config.rs

@@ -6,6 +6,7 @@ use std::process::Command;
 use std::{env, fs};
 
 use clap::{ArgEnum, Parser};
+use clap_complete::Shell;
 use color_eyre::eyre;
 use color_eyre::eyre::Context;
 use color_eyre::eyre::Result;
@@ -489,6 +490,14 @@ pub struct CommandLineArgs {
     /// See: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/struct.EnvFilter.html
     #[clap(long, default_value = "info")]
     pub log_filter: String,
+
+    /// Print completion script for the given shell and exit
+    #[clap(long, arg_enum, hide = true)]
+    pub gen_completion: Option<Shell>,
+
+    /// Print roff manpage and exit
+    #[clap(long, hide = true)]
+    pub gen_manpage: bool,
 }
 
 impl CommandLineArgs {

src/main.rs

@@ -4,6 +4,7 @@ use std::env;
 use std::io;
 use std::process::exit;
 
+use clap::CommandFactory;
 use clap::{crate_version, Parser};
 use color_eyre::eyre::Context;
 use color_eyre::eyre::{eyre, Result};
@@ -42,6 +43,18 @@ fn run() -> Result<()> {
 
     let opt = CommandLineArgs::parse();
 
+    if let Some(shell) = opt.gen_completion {
+        let cmd = &mut CommandLineArgs::command();
+        clap_complete::generate(shell, cmd, clap::crate_name!(), &mut std::io::stdout());
+        return Ok(());
+    }
+
+    if opt.gen_manpage {
+        let man = clap_mangen::Man::new(CommandLineArgs::command());
+        man.render(&mut std::io::stdout())?;
+        return Ok(());
+    }
+
     install_tracing(&opt.tracing_filter_directives())?;
 
     for env in opt.env_variables() {