Move option parsing to crates.io-based getopts crate

Should help adding more options in the future as well!

Cargo.lock

@@ -4,6 +4,7 @@ version = "0.0.1"
 dependencies = [
  "diff 0.1.7 (git+https://github.com/utkarshkukreti/diff.rs.git)",
  "env_logger 0.3.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "getopts 0.2.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustc-serialize 0.3.16 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -41,6 +42,11 @@ dependencies = [
  "regex 0.1.41 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "getopts"
+version = "0.2.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "kernel32-sys"
 version = "0.1.4"

Cargo.toml

@@ -19,5 +19,6 @@ diff = { git = "https://github.com/utkarshkukreti/diff.rs.git" }
 syntex_syntax = { git = "https://github.com/serde-rs/syntex" }
 log = "0.3.2"
 env_logger = "0.3.1"
+getopts = "0.2"
 
 [dev-dependencies]

src/bin/rustfmt.rs

@@ -15,6 +15,7 @@ extern crate log;
 extern crate rustfmt;
 extern crate toml;
 extern crate env_logger;
+extern crate getopts;
 
 use rustfmt::{WriteMode, run};
 use rustfmt::config::Config;
@@ -23,7 +24,8 @@ use std::env;
 use std::fs::{self, File};
 use std::io::{self, Read};
 use std::path::PathBuf;
-use std::str::FromStr;
+
+use getopts::Options;
 
 // Try to find a project file in the current directory and its parents.
 fn lookup_project_file() -> io::Result<PathBuf> {
@@ -52,7 +54,7 @@ fn lookup_and_read_project_file() -> io::Result<(PathBuf, String)> {
 }
 
 fn execute() -> i32 {
-    let (args, write_mode) = match determine_params(std::env::args()) {
+    let (file, write_mode) = match determine_params(std::env::args().skip(1)) {
         Some(params) => params,
         None => return 1,
     };
@@ -65,7 +67,7 @@ fn execute() -> i32 {
         Err(_) => Default::default(),
     };
 
-    run(args, write_mode, &config);
+    run(&file, write_mode, &config);
     0
 }
 
@@ -83,50 +85,52 @@ fn main() {
     std::process::exit(exit_code);
 }
 
-fn print_usage<S: Into<String>>(reason: S) {
-    println!("{}\n\r usage: rustfmt [-h Help] [--write-mode=[replace|overwrite|display|diff]] \
-              <file_name>",
-             reason.into());
+fn print_usage(opts: &Options, reason: &str) {
+    let reason = format!("{}\nusage: {} [options] <file>",
+                         reason,
+                         env::current_exe().unwrap().display());
+    println!("{}", opts.usage(&reason));
     Config::print_docs();
 }
 
-fn determine_params<I>(args: I) -> Option<(Vec<String>, WriteMode)>
+fn determine_params<I>(args: I) -> Option<(PathBuf, WriteMode)>
     where I: Iterator<Item = String>
 {
-    let arg_prefix = "-";
-    let write_mode_prefix = "--write-mode=";
-    let help_mode = "-h";
-    let long_help_mode = "--help";
-    let mut write_mode = WriteMode::Replace;
-    let mut rustc_args = Vec::new();
+    let mut opts = Options::new();
+    opts.optflag("h", "help", "show this message");
+    opts.optopt("",
+                "write-mode",
+                "mode to write in",
+                "[replace|overwrite|display|diff]");
+    let matches = match opts.parse(args) {
+        Ok(m) => m,
+        Err(e) => {
+            print_usage(&opts, &e.to_string());
+            return None;
+        }
+    };
 
-    // The NewFile option currently isn't supported because it requires another
-    // parameter, but it can be added later.
-    for arg in args {
-        if arg.starts_with(write_mode_prefix) {
-            match FromStr::from_str(&arg[write_mode_prefix.len()..]) {
-                Ok(mode) => write_mode = mode,
-                Err(_) => {
-                    print_usage("Unrecognized write mode");
-                    return None;
-                }
-            }
-        } else if arg.starts_with(help_mode) || arg.starts_with(long_help_mode) {
-            print_usage("");
-            return None;
-        } else if arg.starts_with(arg_prefix) {
-            print_usage("Invalid argument");
-            return None;
-        } else {
-            // Pass everything else to rustc
-            rustc_args.push(arg);
-        }
+    if matches.opt_present("h") {
+        print_usage(&opts, "");
     }
 
-    if rustc_args.len() < 2 {
-        print_usage("Please provide a file to be formatted");
+    let write_mode = match matches.opt_str("write-mode") {
+        Some(mode) => {
+            match mode.parse() {
+                Ok(mode) => mode,
+                Err(..) => {
+                    print_usage(&opts, "Unrecognized write mode");
+                    return None;
+                }
+            }
+        }
+        None => WriteMode::Replace,
+    };
+
+    if matches.free.len() != 1 {
+        print_usage(&opts, "Please provide one file to format");
         return None;
     }
 
-    Some((rustc_args, write_mode))
+    Some((PathBuf::from(&matches.free[0]), write_mode))
 }