diff --git a/Makefile b/Makefile
index 34733f74d..fbba2f130 100644
--- a/Makefile
+++ b/Makefile
@@ -58,6 +58,9 @@ BUILD       ?= $(PROGS)
 EXES        := \
   $(sort $(filter $(BUILD),$(filter-out $(DONT_BUILD),$(PROGS))))
 
+CRATES      := \
+  $(sort $(filter $(EXES), $(filter-out md5sum, $(EXES))))
+
 # Programs with usable tests
 TEST_PROGS  := \
   cat \
@@ -89,6 +92,11 @@ clean_$(1):
 endif
 endef
 
+define CRATE_BUILD
+build/$(2): $(1)/$(1).rs
+	$(call command,$(RUSTC) $(RUSTCFLAGS) --crate-type rlib $(1)/$(1).rs --out-dir build)
+endef
+
 # Test exe built rules
 define TEST_BUILD
 test_$(1): tmp/$(1)_test build build/$(1)
@@ -99,7 +107,14 @@ tmp/$(1)_test: $(1)/test.rs
 endef
 
 # Main rules
+ifneq ($(MULTICALL), 1)
 all: build $(EXES_PATHS)
+else
+all: build build/uutils
+
+build/uutils: uutils/uutils.rs $(addprefix build/, $(foreach crate,$(CRATES),$(shell $(RUSTC) --crate-type rlib --crate-file-name $(crate)/$(crate).rs)))
+	$(RUSTC) $(RUSTCFLAGS) -L build/ uutils/uutils.rs -o $@
+endif
 
 test: tmp $(addprefix test_,$(TESTS))
 	$(RM) -rf tmp
@@ -117,5 +132,8 @@ tmp:
 # Creating necessary rules for each targets
 $(foreach exe,$(EXES),$(eval $(call EXE_BUILD,$(exe))))
 $(foreach test,$(TESTS),$(eval $(call TEST_BUILD,$(test))))
+ifeq ($(MULTICALL), 1)
+$(foreach crate,$(CRATES),$(eval $(call CRATE_BUILD,$(crate),$(shell $(RUSTC) --crate-type rlib --crate-file-name --out-dir build $(crate)/$(crate).rs))))
+endif
 
 .PHONY: all test clean
diff --git a/base64/base64.rs b/base64/base64.rs
index 2dc8c9188..a98d81676 100644
--- a/base64/base64.rs
+++ b/base64/base64.rs
@@ -35,8 +35,7 @@ mod util;
 
 static NAME: &'static str = "base64";
 
-fn main() {
-    let args = os::args();
+pub fn uumain(args: Vec<String>) {
     let opts = ~[
         optflag("d", "decode", "decode data"),
         optflag("i", "ignore-garbage", "when decoding, ignore non-alphabetic characters"),
@@ -91,6 +90,10 @@ fn main() {
     }
 }
 
+fn main() {
+    uumain(os::args());
+}
+
 fn decode(input: &mut Reader, ignore_garbage: bool) {
     let mut to_decode = match input.read_to_str() {
         Ok(m) => m,
diff --git a/basename/basename.rs b/basename/basename.rs
index c3364ae9f..f60a6ace7 100644
--- a/basename/basename.rs
+++ b/basename/basename.rs
@@ -23,8 +23,9 @@ mod util;
 static NAME: &'static str = "basename";
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = strip_dir(args.get(0).as_slice());
 
     //
diff --git a/cat/cat.rs b/cat/cat.rs
index ca269ab8f..46ced03a3 100644
--- a/cat/cat.rs
+++ b/cat/cat.rs
@@ -19,8 +19,9 @@ use std::io::{print, File};
 use std::io::stdio::{stdout_raw, stdin_raw};
 use std::io::{BufferedWriter};
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).as_slice();
     let opts = ~[
         getopts::optflag("A", "show-all", "equivalent to -vET"),
diff --git a/cksum/cksum.rs b/cksum/cksum.rs
index b7fc3da5c..bb4d94bfe 100644
--- a/cksum/cksum.rs
+++ b/cksum/cksum.rs
@@ -77,8 +77,9 @@ fn open_file(name: &str) -> IoResult<Box<Reader>> {
     }
 }
 
-pub fn main() {
-    let args = os::args();
+pub fn main() { uumain(os::args()); } 
+
+pub fn uumain(args: Vec<String>) {
     let opts = [
         getopts::optflag("h", "help", "display this help and exit"),
         getopts::optflag("V", "version", "output version information and exit"),
diff --git a/comm/comm.rs b/comm/comm.rs
index 43d3eaa07..b9e2e2f50 100644
--- a/comm/comm.rs
+++ b/comm/comm.rs
@@ -87,8 +87,9 @@ fn open_file(name: &str) -> IoResult<Box<Buffer>> {
     }
 }
 
-pub fn main() {
-    let args = os::args();
+pub fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let opts = [
         getopts::optflag("1", "", "suppress column 1 (lines uniq to FILE1)"),
         getopts::optflag("2", "", "suppress column 2 (lines uniq to FILE2)"),
diff --git a/cp/cp.rs b/cp/cp.rs
index af0c35e5f..074c0e822 100644
--- a/cp/cp.rs
+++ b/cp/cp.rs
@@ -31,8 +31,9 @@ pub enum Mode {
     Version,
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let opts = ~[
         optflag("h", "help", "display this help and exit"),
         optflag("", "version", "output version information and exit"),
diff --git a/dirname/dirname.rs b/dirname/dirname.rs
index 11df43cab..8ae72da43 100644
--- a/dirname/dirname.rs
+++ b/dirname/dirname.rs
@@ -16,8 +16,9 @@ use std::io::print;
 
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("z", "zero", "separate output with NUL rather than newline"),
diff --git a/du/du.rs b/du/du.rs
index a27fa07ca..bc897f033 100644
--- a/du/du.rs
+++ b/du/du.rs
@@ -90,8 +90,9 @@ fn du(path: &Path, mut my_stat: Stat,
     return stats;
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).as_slice();
     let opts = ~[
         // In task
diff --git a/echo/echo.rs b/echo/echo.rs
index 17da759a3..caa49bf9c 100644
--- a/echo/echo.rs
+++ b/echo/echo.rs
@@ -69,8 +69,9 @@ fn convert_str(string: &str, index: uint, base: uint) -> (char, int) {
     return (to_char(&bytes, base), max_digits)
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("n", "", "do not output the trailing newline"),
diff --git a/env/env.rs b/env/env.rs
index 946eaebcd..15a352248 100644
--- a/env/env.rs
+++ b/env/env.rs
@@ -13,6 +13,8 @@
 
 #![allow(non_camel_case_types)]
 
+use std::os;
+
 struct options {
     ignore_env: bool,
     null: bool,
@@ -51,8 +53,9 @@ fn print_env(null: bool) {
     }
 }
 
-fn main() {
-    let args = std::os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let prog = args.get(0).as_slice();
 
     // to handle arguments the same way than GNU env, we can't use getopts
diff --git a/fold/fold.rs b/fold/fold.rs
index 7ab19ae21..2adfffbbf 100644
--- a/fold/fold.rs
+++ b/fold/fold.rs
@@ -26,9 +26,10 @@ mod util;
 static NAME: &'static str = "fold";
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
 
-    let args = os::args();
     let (args, obs_width) = handle_obsolete(args.as_slice());
     let program = args.get(0).clone();
 
diff --git a/groups/groups.rs b/groups/groups.rs
index d46ac19d1..2b2c103db 100644
--- a/groups/groups.rs
+++ b/groups/groups.rs
@@ -25,8 +25,9 @@ use c_types::{get_pw_from_args, group};
 
 static NAME: &'static str = "groups";
 
-fn main () {
-    let args = os::args();
+fn main () { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let options = [
             optflag("h", "", "Help")
         ];
diff --git a/head/head.rs b/head/head.rs
index 150732bd5..e4bbec498 100644
--- a/head/head.rs
+++ b/head/head.rs
@@ -22,11 +22,13 @@ use getopts::{optopt, optflag, getopts, usage};
 
 static PROGRAM: &'static str = "head";
 
-fn main () {
+fn main () { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let mut line_count = 10u;
 
     // handle obsolete -number syntax
-    let options = match obsolete(os::args().tail()) {
+    let options = match obsolete(args.tail()) {
         (args, Some(n)) => { line_count = n; args },
         (args, None) => args
     };
diff --git a/hostid/hostid.rs b/hostid/hostid.rs
index 122a2aa05..b05f4d287 100644
--- a/hostid/hostid.rs
+++ b/hostid/hostid.rs
@@ -49,8 +49,9 @@ extern {
     pub fn gethostid() -> c_long;
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
 
     let opts = [
         optflag("", "help", "display this help and exit"),
diff --git a/hostname/hostname.rs b/hostname/hostname.rs
index 05929c130..af7ec2aaf 100644
--- a/hostname/hostname.rs
+++ b/hostname/hostname.rs
@@ -23,8 +23,9 @@ extern {
     fn sethostname(name: *libc::c_char, namelen: libc::c_int) -> libc::c_int;
 }
 
-fn main () {
-    let args = os::args();
+fn main () { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0);
 
     let options = [
diff --git a/id/id.rs b/id/id.rs
index 3ec427975..3d60d7776 100644
--- a/id/id.rs
+++ b/id/id.rs
@@ -87,8 +87,9 @@ extern {
 
 static NAME: &'static str = "id";
 
-fn main () {
-    let args = os::args();
+fn main () { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let args_t = args.tail();
 
     let options = [
diff --git a/kill/kill.rs b/kill/kill.rs
index ac9fa2591..a8fa7ec67 100644
--- a/kill/kill.rs
+++ b/kill/kill.rs
@@ -53,8 +53,9 @@ pub enum Mode {
 }
 
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
 
     let opts = ~[
         optflag("h", "help", "display this help and exit"),
diff --git a/logname/logname.rs b/logname/logname.rs
index d6b36219a..1149ae8dd 100644
--- a/logname/logname.rs
+++ b/logname/logname.rs
@@ -43,8 +43,9 @@ fn version() {
     println!("{} {}", NAME, VERSION);
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
 
     //
diff --git a/mkdir/mkdir.rs b/mkdir/mkdir.rs
index 7f56bb69d..28956a89d 100644
--- a/mkdir/mkdir.rs
+++ b/mkdir/mkdir.rs
@@ -28,8 +28,9 @@ static VERSION: &'static str = "1.0.0";
 /**
  * Handles option parsing
  */
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
 
     let opts = ~[
         // Linux-specific options, not implemented
diff --git a/paste/paste.rs b/paste/paste.rs
index e76143234..a8556aef9 100644
--- a/paste/paste.rs
+++ b/paste/paste.rs
@@ -23,8 +23,9 @@ mod util;
 static NAME: &'static str = "paste";
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
 
     let opts = ~[
diff --git a/printenv/printenv.rs b/printenv/printenv.rs
index 33ecdc8f4..a167c15e8 100644
--- a/printenv/printenv.rs
+++ b/printenv/printenv.rs
@@ -24,8 +24,9 @@ mod util;
 
 static NAME: &'static str = "printenv";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("0", "null", "end each output line with 0 byte rather than newline"),
diff --git a/pwd/pwd.rs b/pwd/pwd.rs
index 2b007b422..2df6b4c2f 100644
--- a/pwd/pwd.rs
+++ b/pwd/pwd.rs
@@ -23,8 +23,9 @@ mod util;
 static NAME: &'static str = "pwd";
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("", "help", "display this help and exit"),
diff --git a/rm/rm.rs b/rm/rm.rs
index 73d072afc..9da2a5ea1 100644
--- a/rm/rm.rs
+++ b/rm/rm.rs
@@ -29,8 +29,9 @@ enum InteractiveMode {
 
 static NAME: &'static str = "rm";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
 
     // TODO: make getopts support -R in addition to -r
diff --git a/rmdir/rmdir.rs b/rmdir/rmdir.rs
index 136638bf5..fd71a84b2 100644
--- a/rmdir/rmdir.rs
+++ b/rmdir/rmdir.rs
@@ -22,8 +22,9 @@ mod util;
 
 static NAME: &'static str = "rmdir";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
 
     let opts = ~[
diff --git a/seq/seq.rs b/seq/seq.rs
index b44740642..370210489 100644
--- a/seq/seq.rs
+++ b/seq/seq.rs
@@ -33,8 +33,9 @@ fn escape_sequences(s: &str) -> String {
         replace("\\t", "\t")
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let opts = ~[
         getopts::optopt("s", "separator", "Separator character (defaults to \\n)", ""),
         getopts::optopt("t", "terminator", "Terminator character (defaults to separator)", ""),
diff --git a/sleep/sleep.rs b/sleep/sleep.rs
index bddae9858..7380e2597 100644
--- a/sleep/sleep.rs
+++ b/sleep/sleep.rs
@@ -23,8 +23,9 @@ mod util;
 
 static NAME: &'static str = "sleep";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
 
     let opts = ~[
diff --git a/sum/sum.rs b/sum/sum.rs
index 830dec78e..cb7fbbe1f 100644
--- a/sum/sum.rs
+++ b/sum/sum.rs
@@ -76,8 +76,9 @@ fn open(name: &str) -> IoResult<Box<Reader>> {
 	}
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).as_slice();
     let opts = [
         getopts::optflag("r", "", "use the BSD compatible algorithm (default)"),
diff --git a/tac/tac.rs b/tac/tac.rs
index 0256d1e54..adab8f74f 100644
--- a/tac/tac.rs
+++ b/tac/tac.rs
@@ -23,8 +23,9 @@ mod util;
 static NAME: &'static str = "tac";
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
 
     let opts = ~[
diff --git a/tee/tee.rs b/tee/tee.rs
index c3358706a..345cb040d 100644
--- a/tee/tee.rs
+++ b/tee/tee.rs
@@ -24,8 +24,10 @@ use getopts::{getopts, optflag, usage};
 static NAME: &'static str = "tee";
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
-    match options(args().as_slice()).and_then(exec) {
+fn main() { uumain(args()); }
+
+pub fn uumain(args: Vec<String>) {
+    match options(args.as_slice()).and_then(exec) {
         Ok(_) => set_exit_status(0),
         Err(_) => set_exit_status(1)
     }
diff --git a/touch/touch.rs b/touch/touch.rs
index 9c69f6665..25ff0dd48 100644
--- a/touch/touch.rs
+++ b/touch/touch.rs
@@ -22,8 +22,9 @@ mod util;
 static NAME: &'static str = "touch";
 static VERSION: &'static str = "1.0.0";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let opts = ~[
         getopts::optflag("a", "",               "change only the access time"),
         getopts::optflag("c", "no-create",      "do not create any files"),
diff --git a/tr/tr.rs b/tr/tr.rs
index 0212bccf0..f99af6309 100644
--- a/tr/tr.rs
+++ b/tr/tr.rs
@@ -146,8 +146,8 @@ fn usage(opts: &[OptGroup]) {
         print(getopts::usage("Translate or delete characters.", opts).as_slice());
 }
 
-pub fn main() {
-    let args = os::args();
+pub fn main() { uumain(os::args()); }
+pub fn uumain(args: Vec<String>) {
     let opts = [
         getopts::optflag("c", "complement", "use the complement of SET1"),
         getopts::optflag("C", "", "same as -c"),
diff --git a/truncate/truncate.rs b/truncate/truncate.rs
index 30feac64f..ccce94021 100644
--- a/truncate/truncate.rs
+++ b/truncate/truncate.rs
@@ -46,8 +46,9 @@ enum TruncateMode {
 
 static NAME: &'static str = "truncate";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
 
     let opts = ~[
diff --git a/tty/tty.rs b/tty/tty.rs
index dccb5ba98..2a8143756 100644
--- a/tty/tty.rs
+++ b/tty/tty.rs
@@ -34,9 +34,9 @@ extern {
 
 static NAME: &'static str = "tty";
 
-fn main () {
-    let args = os::args();
+fn main () { uumain(os::args()); }
 
+pub fn uumain(args: Vec<String>) {
     let options = [
         optflag("s", "silent", "print nothing, only return an exit status")
     ];
diff --git a/uname/uname.rs b/uname/uname.rs
index a438d1a32..e6cc63316 100644
--- a/uname/uname.rs
+++ b/uname/uname.rs
@@ -51,8 +51,9 @@ unsafe fn getuname() -> utsrust {
 
 static NAME: &'static str = "uname";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).as_slice();
     let opts = ~[
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/unlink/unlink.rs b/unlink/unlink.rs
index aa53a0efb..f4c17b195 100644
--- a/unlink/unlink.rs
+++ b/unlink/unlink.rs
@@ -26,8 +26,9 @@ mod util;
 
 static NAME: &'static str = "unlink";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/uptime/uptime.rs b/uptime/uptime.rs
index 9b1b4e7f5..2dab891cc 100644
--- a/uptime/uptime.rs
+++ b/uptime/uptime.rs
@@ -47,8 +47,9 @@ extern {
     fn utmpxname(file: *c_char) -> c_int;
 }
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("v", "version", "output version information and exit"),
diff --git a/users/users.rs b/users/users.rs
index 8050106e0..52d705a9b 100644
--- a/users/users.rs
+++ b/users/users.rs
@@ -47,8 +47,9 @@ extern {
 
 static NAME: &'static str = "users";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).as_slice();
     let opts = ~[
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/uutils/uutils.rs b/uutils/uutils.rs
new file mode 100644
index 000000000..6a91e6f40
--- /dev/null
+++ b/uutils/uutils.rs
@@ -0,0 +1,151 @@
+#![crate_id(name="uutils", vers="1.0.0", author="Michael Gehring")]
+
+/*
+ * This file is part of the uutils coreutils package.
+ *
+ * (c) Michael Gehring <mg@ebfe.org>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+extern crate collections;
+extern crate getopts;
+
+extern crate base64;
+extern crate basename;
+extern crate cat;
+extern crate cksum;
+extern crate comm;
+extern crate cp;
+extern crate dirname;
+extern crate du;
+extern crate echo;
+extern crate env;
+extern crate fold;
+extern crate groups;
+extern crate head;
+extern crate hostid;
+extern crate hostname;
+extern crate id;
+extern crate kill;
+extern crate logname;
+extern crate mkdir;
+extern crate paste;
+extern crate printenv;
+extern crate pwd;
+extern crate rm;
+extern crate rmdir;
+extern crate seq;
+extern crate sleep;
+extern crate sum;
+extern crate tac;
+extern crate tee;
+extern crate touch;
+extern crate tr;
+extern crate truncate;
+extern crate tty;
+extern crate uname;
+extern crate unlink;
+extern crate uptime;
+extern crate users;
+extern crate wc;
+extern crate whoami;
+extern crate yes;
+
+use std::os;
+use collections::hashmap::HashMap;
+
+static NAME: &'static str = "uutils";
+static VERSION: &'static str = "1.0.0";
+
+fn util_map() -> HashMap<&str, fn(Vec<String>)> {
+    fn uutrue(_: Vec<String>) { os::set_exit_status(0); }
+    fn uufalse(_: Vec<String>) { os::set_exit_status(1); }
+
+    let mut map = HashMap::new();
+    map.insert("base64", base64::uumain);
+    map.insert("basename", basename::uumain);
+    map.insert("cat", cat::uumain);
+    map.insert("cksum", cksum::uumain);
+    map.insert("comm", comm::uumain);
+    map.insert("cp", cp::uumain);
+    map.insert("dirname", dirname::uumain);
+    map.insert("du", du::uumain);
+    map.insert("echo", echo::uumain);
+    map.insert("env", env::uumain);
+    map.insert("false", uufalse);
+    map.insert("fold", fold::uumain);
+    map.insert("groups", groups::uumain);
+    map.insert("head", head::uumain);
+    map.insert("hostid", hostid::uumain);
+    map.insert("hostname", hostname::uumain);
+    map.insert("id", id::uumain);
+    map.insert("kill", kill::uumain);
+    map.insert("logname", logname::uumain);
+    map.insert("mkdir", mkdir::uumain);
+    map.insert("paste", paste::uumain);
+    map.insert("printenv", printenv::uumain);
+    map.insert("pwd", pwd::uumain);
+    map.insert("rm", rm::uumain);
+    map.insert("rmdir", rmdir::uumain);
+    map.insert("seq", seq::uumain);
+    map.insert("sleep", sleep::uumain);
+    map.insert("sum", sum::uumain);
+    map.insert("tac", tac::uumain);
+    map.insert("tee", tee::uumain);
+    map.insert("touch", touch::uumain);
+    map.insert("tr", tr::uumain);
+    map.insert("true", uutrue);
+    map.insert("truncate", truncate::uumain);
+    map.insert("tty", tty::uumain);
+    map.insert("uname", uname::uumain);
+    map.insert("unlink", unlink::uumain);
+    map.insert("uptime", uptime::uumain);
+    map.insert("users", users::uumain);
+    map.insert("wc", wc::uumain);
+    map.insert("whoami", whoami::uumain);
+    map.insert("yes", yes::uumain);
+    map
+}
+
+fn usage(cmap: &HashMap<&str, fn(Vec<String>)>) {
+        println!("{} {}", NAME, VERSION);
+        println!("");
+        println!("Usage:");
+        println!("  {} [util [arguments...]", NAME);
+        println!("Utils:");
+        let mut utils: Vec<&str> = cmap.keys().map(|&s| s).collect();
+        utils.sort();
+        for util in utils.iter() {
+            println!("\t{}", util);
+        }
+}
+
+fn main() {
+    let umap = util_map();
+    let mut args = os::args();
+
+    // try binary name as util name.
+    let binary = Path::new(args.get(0).as_slice());
+    let util = binary.filename_str().unwrap();
+    if umap.contains_key(&util) {
+        let &uumain = umap.get(&util);
+        uumain(args);
+        return
+    }
+
+    // try first arg as util name.
+    if args.len() >= 2 {
+        args.shift();
+        let util = args.get(0).as_slice().clone();
+        if umap.contains_key(&util) {
+            let &uumain = umap.get(&util);
+            uumain(args.clone());
+            return
+        }
+    }
+
+    usage(&umap);
+    os::set_exit_status(1);
+}
diff --git a/wc/wc.rs b/wc/wc.rs
index 1db8730ec..7ae4fd197 100644
--- a/wc/wc.rs
+++ b/wc/wc.rs
@@ -33,8 +33,9 @@ struct Result {
 
 static NAME: &'static str = "wc";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("c", "bytes", "print the byte counts"),
diff --git a/whoami/whoami.rs b/whoami/whoami.rs
index 75fd62107..21e870034 100644
--- a/whoami/whoami.rs
+++ b/whoami/whoami.rs
@@ -41,8 +41,9 @@ unsafe fn getusername() -> String {
 
 static NAME: &'static str = "whoami";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).as_slice();
     let opts = ~[
         getopts::optflag("h", "help", "display this help and exit"),
diff --git a/yes/yes.rs b/yes/yes.rs
index f846d9892..745390ae3 100644
--- a/yes/yes.rs
+++ b/yes/yes.rs
@@ -24,8 +24,9 @@ mod util;
 
 static NAME: &'static str = "yes";
 
-fn main() {
-    let args = os::args();
+fn main() { uumain(os::args()); }
+
+pub fn uumain(args: Vec<String>) {
     let program = args.get(0).clone();
     let opts = ~[
         getopts::optflag("h", "help", "display this help and exit"),