Add a separate completion generation

To be able to include zsh bindings in packaging and not add a subcommand
to arch-rebuild-order add a new binary for generating completions to
'OUT_DIR'.

Closes: #9

Cargo.toml

@@ -12,6 +12,7 @@ license-file = "LICENSE"
 keywords = ["archlinux", "build", "alpm"]
 categories = ["command-line-utilities"]
 publish = false
+default-run = "arch-rebuild-order"
 
 [dependencies]
 alpm = "1"

Makefile

 PREFIX ?= /usr/local
 BINDIR ?= $(PREFIX)/bin
 MANDIR ?= $(PREFIX)/share/man
+OUT_DIR ?= target
 
 # Tools
 
@@ -20,8 +21,13 @@ doc: $(DOCDIR)/$(MANPAGE)
 build:
 	$(CARGO) build --release --locked
 
+completions:
+	OUT_DIR=$(OUT_DIR) $(CARGO) run --bin completions
 
 .PHONY: install
-install: doc
+install: build completions doc
 	install -Dm755 target/release/$(BIN) $(DESTDIR)$(BINDIR)/$(BIN)
 	install -Dm644 $(DOCDIR)/$(MANPAGE) $(DESTDIR)$(MANDIR)/man1/$(MANPAGE)
+	install -Dm644 target/_$(BIN) $(DESTDIR)$(PREFIX)/share/zsh/site-functions/_$(BIN)
+	install -Dm644 target/$(BIN).bash $(DESTDIR)$(PREFIX)/share/bash-completion/$(BIN)
+	install -Dm644 target/$(BIN).fish $(DESTDIR)$(PREFIX)/share/fish/vendor_completions.d/$(BIN)

README.md

@@ -38,3 +38,8 @@ dot -Tpng opencolorio.dot > opencolorio.png
 
 * `testing` and `community-testing` repositories are not included.
 * Rebuilder expects an up-to-date syncdb and does not provide warning if it is not.
+
+## Completions
+
+Shell completions can be created with `cargo run --bin completions` in a
+directory specified by the env variable `OUT_DIR`.

src/args.rs

+use structopt::StructOpt;
+
+#[derive(Debug, StructOpt)]
+#[structopt(name = "arch-rebuild-order", about, author)]
+pub struct Args {
+    /// List of input packages
+    #[structopt(min_values = 1, required = true)]
+    pub pkgnames: Vec<String>,
+
+    /// Repositories
+    #[structopt(
+        default_value = "core,extra,community,multilib",
+        long,
+        use_delimiter = true
+    )]
+    pub repos: Vec<String>,
+
+    /// The path to the pacman database, default ( /var/lib/pacman )
+    #[structopt(long)]
+    pub dbpath: Option<String>,
+
+    /// Write a dotfile into the given file
+    #[structopt(short, long)]
+    pub dotfile: Option<String>,
+}

src/bin/completions.rs

+use std::{env, str::FromStr};
+use structopt::clap::Shell;
+use structopt::StructOpt;
+
+use arch_rebuild_order::args::Args;
+
+fn main() {
+    //  https://doc.rust-lang.org/cargo/reference/environment-variables.html
+    let out_dir = env::var_os("OUT_DIR").expect("out dir not set");
+    let mut app = Args::clap();
+    for variant in &Shell::variants() {
+        let variant = Shell::from_str(variant).unwrap();
+        app.gen_completions("arch-rebuild-order", variant, &out_dir);
+    }
+    println!("completion scripts generated in {:?}", out_dir);
+}

src/lib.rs

@@ -7,6 +7,8 @@ use std::error::Error;
 use std::fs::File;
 use std::io::{BufWriter, Write};
 
+pub mod args;
+
 const ROOT_DIR: &str = "/";
 const DB_PATH: &str = "/var/lib/pacman/";
 

src/main.rs

 use structopt::StructOpt;
 
-#[derive(Debug, StructOpt)]
-#[structopt(name = "arch-rebuild-order", about, author)]
-struct Args {
-    /// List of input packages
-    #[structopt(min_values = 1, required = true)]
-    pkgnames: Vec<String>,
-
-    /// Repositories
-    #[structopt(
-        default_value = "core,extra,community,multilib",
-        long,
-        use_delimiter = true
-    )]
-    repos: Vec<String>,
-
-    /// The path to the pacman database, default ( /var/lib/pacman )
-    #[structopt(long)]
-    dbpath: Option<String>,
-
-    /// Write a dotfile into the given file
-    #[structopt(short, long)]
-    dotfile: Option<String>,
-}
+use arch_rebuild_order::args::Args;
 
 fn main() {
     let args = Args::from_args();