Add the ability to generate shell completions

Author: fgimian

Cargo.lock

@@ -30,6 +30,7 @@ trash-move = ["trash"]
 
 [dependencies]
 clap = { version = "4.0.29", features = ["derive"] }
+clap_complete = "4.5.54"
 jwalk = "0.8.1"
 byte-unit = "4"
 atty = "0.2.11"

Cargo.toml

@@ -1,6 +1,6 @@
 #![forbid(rust_2018_idioms, unsafe_code)]
 use anyhow::Result;
-use clap::Parser;
+use clap::{CommandFactory as _, Parser};
 use dua::{canonicalize_ignore_dirs, TraversalSorting};
 use log::info;
 use simplelog::{Config, LevelFilter, WriteLogger};
@@ -141,6 +141,11 @@ fn main() -> Result<()> {
             }
             res
         }
+        Some(Completions { shell }) => {
+            let mut cmd = options::Args::command();
+            clap_complete::generate(shell, &mut cmd, "dua", &mut io::stdout());
+            return Ok(());
+        }
         None => {
             let stdout = io::stdout();
             let stdout_locked = stdout.lock();

src/main.rs

@@ -1,3 +1,4 @@
+use clap_complete::Shell;
 use dua::ByteFormat as LibraryByteFormat;
 use std::path::PathBuf;
 
@@ -123,4 +124,9 @@ pub enum Command {
         #[clap(value_parser)]
         input: Vec<PathBuf>,
     },
+    /// Generate shell completions
+    Completions {
+        #[clap()]
+        shell: Shell,
+    },
 }