feat: add help and version command line arguments

Cargo.lock

@@ -195,6 +195,12 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "anyhow"
+version = "1.0.97"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dcfed56ad506cb2c684a14971b8861fdc3baaaae314b9e5f9bb532cbe3ba7a4f"
+
 [[package]]
 name = "apply"
 version = "0.3.0"
@@ -1159,6 +1165,7 @@ dependencies = [
  "greetd_ipc",
  "i18n-embed",
  "i18n-embed-fl",
+ "lexopt",
  "libcosmic",
  "log",
  "logind-zbus",
@@ -1170,6 +1177,7 @@ dependencies = [
  "shlex",
  "tokio",
  "upower_dbus",
+ "vergen",
  "wayland-client",
  "xdg",
  "xkb-data",
@@ -3187,6 +3195,12 @@ version = "1.3.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "830d08ce1d1d941e6b30645f1a0eb5643013d835ce3779a5fc208261dbe10f55"
 
+[[package]]
+name = "lexopt"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "baff4b617f7df3d896f97fe922b64817f6cd9a756bb81d40f8883f2f66dcb401"
+
 [[package]]
 name = "libc"
 version = "0.2.171"
@@ -3689,6 +3703,15 @@ dependencies = [
  "syn 2.0.100",
 ]
 
+[[package]]
+name = "num_threads"
+version = "0.1.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5c7398b9c8b70908f6371f47ed36737907c87c52af34c268fed0bf0ceb92ead9"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "objc"
 version = "0.2.7"
@@ -5257,7 +5280,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9d9c75b47bdff86fa3334a3db91356b8d7d86a9b839dab7d0bdc5c3d3a077618"
 dependencies = [
  "deranged",
+ "itoa",
+ "libc",
  "num-conv",
+ "num_threads",
  "powerfmt",
  "serde",
  "time-core",
@@ -5662,6 +5688,18 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b6c140620e7ffbb22c2dee59cafe6084a59b5ffc27a8859a5f0d494b5d52b6be"
 
+[[package]]
+name = "vergen"
+version = "8.3.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2990d9ea5967266ea0ccf413a4aa5c42a93dbcfda9cb49a97de6931726b12566"
+dependencies = [
+ "anyhow",
+ "cfg-if",
+ "rustversion",
+ "time",
+]
+
 [[package]]
 name = "version_check"
 version = "0.9.5"

Cargo.toml

@@ -3,6 +3,9 @@ name = "cosmic-greeter"
 version = "0.1.0"
 edition = "2024"
 
+[build-dependencies]
+vergen = { version = "8", features = ["git", "gitcl"] }
+
 [dependencies]
 chrono = { version = "0.4", features = ["unstable-locales"] }
 cosmic-bg-config.workspace = true
@@ -42,6 +45,8 @@ nix = { workspace = true, optional = true }
 upower_dbus = { git = "https://github.com/pop-os/dbus-settings-bindings", rev = "badfc6a", optional = true }
 # Required for some features
 zbus = { workspace = true, optional = true }
+# CLI arguments
+lexopt = "0.3.0"
 # Internationalization
 i18n-embed = { version = "0.14", features = [
     "fluent-system",

build.rs

@@ -0,0 +1,5 @@
+use vergen::EmitBuilder;
+
+fn main() {
+    EmitBuilder::builder().git_sha(true).emit().unwrap();
+}

src/main.rs

@@ -3,7 +3,30 @@
 
 use cosmic_greeter::{greeter, locker};
 
+use lexopt::{Arg, Parser};
+
 fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let mut parser = Parser::from_env();
+
+    // Parse the arguments
+    while let Some(arg) = parser.next()? {
+        match arg {
+            Arg::Short('h') | Arg::Long("help") => {
+                print_help(env!("CARGO_PKG_VERSION"), env!("VERGEN_GIT_SHA"));
+                return Ok(());
+            }
+            Arg::Short('v') | Arg::Long("version") => {
+                println!(
+                    "cosmic-greeter {} (git commit {})",
+                    env!("CARGO_PKG_VERSION"),
+                    env!("VERGEN_GIT_SHA")
+                );
+                return Ok(());
+            }
+            _ => {}
+        }
+    }
+
     match pwd::Passwd::current_user() {
         Some(current_user) => match current_user.name.as_str() {
             "cosmic-greeter" => greeter::main(),
@@ -12,3 +35,19 @@ fn main() -> Result<(), Box<dyn std::error::Error>> {
         _ => Err("failed to determine current user".into()),
     }
 }
+
+fn print_help(version: &str, git_rev: &str) {
+    println!(
+        r#"cosmic-greeter {version} (git commit {git_rev})
+System76 <info@system76.com>
+
+Designed for the COSMIC™ desktop environment, cosmic-greeter is a libcosmic
+frontend for greetd which can be run inside of cosmic-comp.
+
+Project home page: https://github.com/pop-os/cosmic-greeter
+
+Options:
+  -h, --help     Show this message
+  -v, --version  Show the version of cosmic-greeter"#
+    );
+}