implement `clean` subcommand (#583)

src/bin/clean.rs

@@ -0,0 +1,30 @@
+use std::fs;
+use std::path::PathBuf;
+use clap::{App, ArgMatches, SubCommand};
+use mdbook::MDBook;
+use mdbook::errors::*;
+use get_book_dir;
+
+// Create clap subcommand arguments
+pub fn make_subcommand<'a, 'b>() -> App<'a, 'b> {
+    SubCommand::with_name("clean")
+        .about("Delete built book")
+        .arg_from_usage(
+            "-d, --dest-dir=[dest-dir] 'The directory of built book{n}(Defaults to ./book when \
+             omitted)'",
+        )
+}
+
+// Clean command implementation
+pub fn execute(args: &ArgMatches) -> ::mdbook::errors::Result<()> {
+    let book_dir = get_book_dir(args);
+    let book = MDBook::load(&book_dir)?;
+
+    let dir_to_remove = match args.value_of("dest-dir") {
+        Some(dest_dir) => PathBuf::from(dest_dir),
+        None => book.root.join(&book.config.build.build_dir),
+    };
+    fs::remove_dir_all(&dir_to_remove).chain_err(|| "Unable to remove the build directory")?;
+
+    Ok(())
+}

src/bin/mdbook.rs

@@ -19,6 +19,7 @@ use env_logger::Builder;
 use mdbook::utils;
 
 pub mod build;
+pub mod clean;
 pub mod init;
 pub mod test;
 #[cfg(feature = "serve")]
@@ -44,7 +45,8 @@ fn main() {
                              at: https://github.com/rust-lang-nursery/mdBook")
                 .subcommand(init::make_subcommand())
                 .subcommand(build::make_subcommand())
-                .subcommand(test::make_subcommand());
+                .subcommand(test::make_subcommand())
+                .subcommand(clean::make_subcommand());
 
     #[cfg(feature = "watch")]
     let app = app.subcommand(watch::make_subcommand());
@@ -55,6 +57,7 @@ fn main() {
     let res = match app.get_matches().subcommand() {
         ("init", Some(sub_matches)) => init::execute(sub_matches),
         ("build", Some(sub_matches)) => build::execute(sub_matches),
+        ("clean", Some(sub_matches)) => clean::execute(sub_matches),
         #[cfg(feature = "watch")]
         ("watch", Some(sub_matches)) => watch::execute(sub_matches),
         #[cfg(feature = "serve")]