Merge pull request #156 from Fiedzia/hostid

implement hostid

Makefile

@@ -30,6 +30,7 @@ PROGS       := \
   head \
 
 UNIX_PROGS := \
+  hostid \
   kill \
   logname \
   users \

README.md

@@ -94,7 +94,6 @@ To do
 - fmt
 - getlimits
 - group-list
-- hostid
 - install
 - join
 - lbracket

hostid/hostid.rs

@@ -0,0 +1,111 @@
+#![crate_id(name="hostid", vers="0.0.1", author="Maciej Dziardziel")]
+#![feature(macro_rules)]
+#![feature(phase)]
+
+/*
+ * This file is part of the uutils coreutils package.
+ *
+ * (c) Maciej Dziardziel <fiedzia@gmail.com>
+ *
+ * For the full copyright and license information, please view the LICENSE file
+ * that was distributed with this source code.
+ */
+
+
+extern crate getopts;
+extern crate collections;
+extern crate serialize;
+
+
+#[phase(syntax, link)] extern crate log;
+
+use std::os;
+
+use getopts::{
+    getopts,
+    optflag,
+    usage,
+};
+
+use std::libc::{c_long};
+
+#[path = "../common/util.rs"]
+mod util;
+
+static NAME:     &'static str = "hostid";
+static VERSION:  &'static str = "0.0.1";
+
+static EXIT_ERR: i32 = 1;
+
+pub enum Mode {
+    HostId,
+    Help,
+    Version,
+}
+
+//currently rust libc interface doesn't include gethostid
+extern {
+    pub fn gethostid() -> c_long;
+}
+
+fn main() {
+    let args = os::args();
+
+    let opts = ~[
+        optflag("", "help", "display this help and exit"),
+        optflag("", "version", "output version information and exit"),
+    ];
+
+    let usage = usage("[options]", opts);
+
+
+    let matches = match getopts(args.tail(), opts) {
+        Ok(m) => m,
+        Err(e) => {
+            show_error!(EXIT_ERR, "{}\n{}", e.to_err_msg(),  get_help_text(NAME, usage));
+            return
+        },
+    };
+
+    let mode = if matches.opt_present("version") {
+        Version
+    } else if matches.opt_present("help") {
+        Help
+    } else {
+        HostId
+    };
+
+    match mode {
+        HostId  => hostid(),
+        Help    => help(NAME, usage),
+        Version => version(),
+    }
+}
+
+fn version() {
+    println!("{} {}", NAME, VERSION);
+}
+
+fn get_help_text(progname: &str, usage: &str) -> ~str {
+    let msg = format!("Usage: \n {0} {1}", progname, usage);
+    msg
+}
+
+fn help(progname: &str, usage: &str) {
+    println!("{}", get_help_text(progname, usage));
+}
+
+fn hostid() {
+
+  /* POSIX says gethostid returns a "32-bit identifier" but is silent
+     whether it's sign-extended.  Turn off any sign-extension.  This
+     is a no-op unless unsigned int is wider than 32 bits.  */
+
+    let mut result:c_long;
+    unsafe {
+        result = gethostid();
+    }
+    
+    result &= 0xffffffff; 
+    println!("{:0>8x}", result);
+}