Implement CLI

Cargo.lock

@@ -55,6 +55,15 @@ version = "1.2.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "1847abb9cb65d566acd5942e94aea9c8f547ad02c98e1649326fc0e8910b8b1e"
 
+[[package]]
+name = "getopts"
+version = "0.2.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "14dbbfd5c71d70241ecf9e6f13737f7b5ce823821063188d7e46c41d371eebd5"
+dependencies = [
+ "unicode-width",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.11.2"
@@ -184,6 +193,12 @@ version = "1.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "55937e1799185b12863d447f42597ed69d9928686b8d88a1df17376a097d8369"
 
+[[package]]
+name = "unicode-width"
+version = "0.1.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3ed742d4ea2bd1176e236172c8429aaf54486e7ac098db29ffe6529e0ce50973"
+
 [[package]]
 name = "unicode-xid"
 version = "0.2.2"
@@ -204,6 +219,7 @@ name = "xremap"
 version = "0.1.0"
 dependencies = [
  "evdev",
+ "getopts",
  "nix",
  "serde",
  "serde_yaml",

Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 
 [dependencies]
 evdev = "0.11.3"
+getopts = "0.2"
 nix = "0.23.1"
 serde = { version = "1.0", features = ["derive"] }
 serde_yaml = "0.8"

src/main.rs

@@ -1,9 +1,12 @@
 use evdev::EventType;
 use std::env;
+use getopts::Options;
 use std::error::Error;
 use std::process::exit;
 use crate::config::Config;
 
+extern crate getopts;
+
 mod config;
 mod input;
 mod output;
@@ -33,15 +36,32 @@ fn event_loop(_config: &Config) -> Result<(), Box<dyn Error>> {
     }
 }
 
+fn usage(program: &str, opts: Options) -> String {
+    let brief = format!("Usage: {} CONFIG [options]", program);
+    opts.usage(&brief)
+}
+
 fn abort(message: &str) -> ! {
     println!("{}", message);
     exit(1);
 }
 
 fn main() {
-    let filename = match env::args().nth(1) {
-        Some(filename) => filename,
-        None => abort("Usage: xremap <file>"),
+    let argv: Vec<String> = env::args().collect();
+    let program = argv[0].clone();
+
+    let mut opts = Options::new();
+    opts.optmulti("", "device", "device name or path", "NAME");
+    opts.optflag("h", "help", "print this help menu");
+
+    let args = match opts.parse(&argv[1..]) {
+        Ok(args) => args,
+        Err(e) => abort(&e.to_string()),
+    };
+
+    let filename = match &args.free.iter().map(String::as_str).collect::<Vec<&str>>()[..] {
+        &[filename] => filename,
+        &[..] => abort(&usage(&program, opts)),
     };
     let config = match config::load_config(&filename) {
         Ok(config) => config,