Add version command line argument

* -V and --version now print the program version and exit
* Use the `exitcode` crate
* Rename `options` variable to `accepted_args`, which seems clearer
  given its usage.

3 files changed, 21 insertions, 2 deletions

diff --git a/Cargo.lock b/Cargo.lock
index 57aaf77..ddb95b6 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -34,6 +34,12 @@ dependencies = [
 ]
 
 [[package]]
+name = "exitcode"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "de853764b47027c2e862a995c34978ffa63c1501f2e15f987ba11bd4f9bba193"
+
+[[package]]
 name = "gag"
 version = "0.1.9"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -102,6 +108,7 @@ name = "passextract"
 version = "0.5.0"
 dependencies = [
  "clipboard",
+ "exitcode",
  "rustty",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 368b968..58bf90f 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -4,4 +4,5 @@ version = "0.5.0"
 
 [dependencies]
 clipboard = "0.1.2"
+exitcode = "1.1.2"
 rustty = "0.1"
diff --git a/src/main.rs b/src/main.rs
index fbbd252..38a6d3b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,6 +4,7 @@
 // file for more information.
 
 extern crate clipboard;
+extern crate exitcode;
 extern crate rustty;
 
 use clipboard::ClipboardContext;
@@ -114,7 +115,17 @@ fn main() {
     // TODO: Add --version -V arg
     // TODO: When done, update man page
 
-    let options = ["-i"];
+    let accepted_args = ["-i", "-V", "--version"];
+
+    match args.get(1) {
+        Some(arg) => {
+            if arg == "-V" || arg == "--version" {
+                println!("{}", env!("CARGO_PKG_VERSION"));
+                process::exit(exitcode::OK);
+            }
+        }
+        None => (),
+    }
 
     let hide_password = match args.get(1) {
         Some(arg) if arg == "-i" => true,
@@ -124,7 +135,7 @@ fn main() {
 
     let last_arg = &args[args.len() - 1];
     let input = if args.len() > 1 &&
-            !options.contains(&last_arg.as_ref()) {
+            !accepted_args.contains(&last_arg.as_ref()) {
         last_arg
     } else {
         "-"