Implement dirname

Makefile

@@ -9,6 +9,7 @@ RMFLAGS     :=
 # Output names
 EXES        := \
   cat \
+  dirname \
   echo \
   env \
   false \

dirname/dirname.rs

@@ -0,0 +1,70 @@
+#[link(name="dirname", vers="1.0.0", author="Derek Chiang")];
+
+/*
+ * This file is part of the uutils coreutils package.
+ *
+ * (c) Derek Chiang <derekchiang93@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+extern mod extra;
+
+use std::os;
+use std::io::stderr;
+use extra::getopts::groups;
+
+static VERSION: &'static str = "1.0.0";
+
+fn main() {
+    let args = os::args();
+    let program = args[0].clone();
+    let opts = ~[
+        groups::optflag("z", "zero", "separate output with NUL rather than newline"),
+        groups::optflag("", "help", "display this help and exit"),
+        groups::optflag("", "version", "output version information and exit"),
+    ];
+
+    let matches = match groups::getopts(args.tail(), opts) {
+        Ok(m) => m,
+        Err(f) => {
+            writeln!(&mut stderr() as &mut Writer,
+                "Invalid options\n{}", f.to_err_msg());
+            os::set_exit_status(1);
+            return
+        }  
+    };
+
+    if matches.opt_present("help") {
+        println("dirname " + VERSION + " - strip last component from file name");
+        println("");
+        println("Usage:");
+        println!("  {0:s} [OPTION] NAME...", program);
+        println("");
+        print(groups::usage("Output each NAME with its last non-slash component and trailing slashes\
+removed; if NAME contains no  /'s,  output  '.'  (meaning  the  current\
+directory).", opts));
+        return;
+    }
+
+    if matches.opt_present("version") {
+        return println("dirname version: " + VERSION);
+    }
+
+    let separator = match matches.opt_present("zero") {
+        true => "\0",
+        false => "\n"
+    };
+
+    if !matches.free.is_empty() {
+        for path in matches.free.iter() {
+            let p = std::path::Path::init(path.clone());
+            print(std::str::from_utf8_slice(p.dirname()));
+            print(separator);
+        }
+    } else {
+        println!("{0:s}: missing operand", program);
+        println!("Try '{0:s} --help' for more information.", program);
+    }
+}