diff --git a/Cargo.lock b/Cargo.lock
index 97fe81a..4727635 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -4,6 +4,7 @@ version = "0.1.5"
 dependencies = [
  "clap 2.13.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "regex 0.1.77 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempdir 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -61,6 +62,14 @@ dependencies = [
  "libc 0.2.16 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand"
+version = "0.3.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "regex"
 version = "0.1.77"
@@ -83,6 +92,14 @@ name = "strsim"
 version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "tempdir"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "term_size"
 version = "0.2.1"
@@ -148,9 +165,11 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum kernel32-sys 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)" = "7507624b29483431c0ba2d82aece8ca6cdba9382bff4ddd0f7490560c056098d"
 "checksum libc 0.2.16 (registry+https://github.com/rust-lang/crates.io-index)" = "408014cace30ee0f767b1c4517980646a573ec61a57957aeeabcac8ac0a02e8d"
 "checksum memchr 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "d8b629fb514376c675b98c1421e80b151d3817ac42d7c667717d282761418d20"
+"checksum rand 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)" = "2791d88c6defac799c3f20d74f094ca33b9332612d9aef9078519c82e4fe04a5"
 "checksum regex 0.1.77 (registry+https://github.com/rust-lang/crates.io-index)" = "64b03446c466d35b42f2a8b203c8e03ed8b91c0f17b56e1f84f7210a257aa665"
 "checksum regex-syntax 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "279401017ae31cf4e15344aa3f085d0e2e5c1e70067289ef906906fdbe92c8fd"
 "checksum strsim 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "50c069df92e4b01425a8bf3576d5d417943a6a7272fbabaf5bd80b1aaa76442e"
+"checksum tempdir 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "87974a6f5c1dfb344d733055601650059a3363de2a6104819293baff662132d6"
 "checksum term_size 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "3f7f5f3f71b0040cecc71af239414c23fd3c73570f5ff54cf50e03cef637f2a0"
 "checksum thread-id 2.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "a9539db560102d1cef46b8b78ce737ff0bb64e7e18d35b2a5688f7d097d0ff03"
 "checksum thread_local 0.2.7 (registry+https://github.com/rust-lang/crates.io-index)" = "8576dbbfcaef9641452d5cf0df9b0e7eeab7694956dd33bb61515fb8f18cfdd5"
diff --git a/Cargo.toml b/Cargo.toml
index a6abcd5..1d08ba8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -10,3 +10,4 @@ homepage = "https://github.com/casey/j"
 
 regex = "^0.1.77"
 clap = "^2.0.0"
+tempdir = "^0.3.5"
diff --git a/justfile b/justfile
index b01bbda..bfb2985 100644
--- a/justfile
+++ b/justfile
@@ -1,6 +1,6 @@
 test:
 	cargo test --lib
-	cargo run -- quine
+	cargo run -- quine clean > /dev/null 2> /dev/null
 
 # list all recipies
 list:
diff --git a/notes b/notes
index 3479937..5bfc695 100644
--- a/notes
+++ b/notes
@@ -2,12 +2,11 @@ notes
 -----
 
 -- report double compile error
--- actually run recipes
--- actually parse recipe and validate contents
--- think about maybe using multiple cores
 -- should pre-requisite order really be arbitrary?
 -- test plan order
 
+-- use multiple cores
+
 - look through all justfiles for features of make that I use. so far:
   . phony
   . SHELL := zsh
diff --git a/src/lib.rs b/src/lib.rs
index adf2050..8f17aae 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -5,7 +5,7 @@ extern crate regex;
 
 use std::io::prelude::*;
 
-use std::{fs, fmt};
+use std::{fs, fmt, process, io};
 use std::collections::{BTreeMap, BTreeSet, HashSet};
 use std::fmt::Display;
 use regex::Regex;
@@ -49,14 +49,46 @@ struct Recipe<'a> {
   dependencies:       BTreeSet<&'a str>,
 }
 
+#[cfg(unix)]
+fn error_from_signal<'a>(recipe: &'a str, exit_status: process::ExitStatus) -> RunError<'a> {
+  use std::os::unix::process::ExitStatusExt;
+  match exit_status.signal() {
+    Some(signal) => RunError::Signal{recipe: recipe, signal: signal},
+    None => RunError::UnknownFailure{recipe: recipe},
+  }
+}
+
+#[cfg(windows)]
+fn error_from_signal<'a>(recipe: &'a str, exit_status: process::ExitStatus) -> RunError<'a> {
+  RunError::UnknownFailure{recipe: recipe}
+}
+
 impl<'a> Recipe<'a> {
   fn run(&self) -> Result<(), RunError<'a>> {
-    // TODO: actually run recipes
-    warn!("running {}", self.name);
     for command in &self.commands {
-     warn!("{}", command);
+      let mut command = *command;
+      if !command.starts_with("@") {
+        warn!("{}", command);
+      } else {
+        command = &command[1..]; 
+      }
+      let status = process::Command::new("sh")
+        .arg("-c")
+        .arg(command)
+        .status();
+      try!(match status {
+        Ok(exit_status) => if let Some(code) = exit_status.code() {
+          if code == 0 {
+            Ok(())
+          } else {
+            Err(RunError::Code{recipe: self.name, code: code})
+          }
+        } else {
+          Err(error_from_signal(self.name, exit_status))
+        },
+        Err(io_error) => Err(RunError::IoError{recipe: self.name, io_error: io_error})
+      });
     }
-    // Err(RunError::Code{recipe: self.name, code: -1})
     Ok(())
   }
 }
@@ -270,10 +302,13 @@ impl<'a> Justfile<'a> {
   }
 }
 
+#[derive(Debug)]
 pub enum RunError<'a> {
   UnknownRecipes{recipes: Vec<&'a str>},
-  // Signal{recipe: &'a str, signal: i32},
+  Signal{recipe: &'a str, signal: i32},
   Code{recipe: &'a str, code: i32},
+  UnknownFailure{recipe: &'a str},
+  IoError{recipe: &'a str, io_error: io::Error},
 }
 
 impl<'a> Display for RunError<'a> {
@@ -289,6 +324,19 @@ impl<'a> Display for RunError<'a> {
       &RunError::Code{recipe, code} => {
         try!(write!(f, "Recipe \"{}\" failed with code {}", recipe, code));
       },
+      &RunError::Signal{recipe, signal} => {
+        try!(write!(f, "Recipe \"{}\" wast terminated by signal {}", recipe, signal));
+      }
+      &RunError::UnknownFailure{recipe} => {
+        try!(write!(f, "Recipe \"{}\" failed for an unknown reason", recipe));
+      },
+      &RunError::IoError{recipe, ref io_error} => {
+        try!(match io_error.kind() {
+          io::ErrorKind::NotFound => write!(f, "Recipe \"{}\" could not be run because j could not find `sh` the command:\n{}", recipe, io_error),
+          io::ErrorKind::PermissionDenied => write!(f, "Recipe \"{}\" could not be run because j could not run `sh`:\n{}", recipe, io_error),
+          _ => write!(f, "Recipe \"{}\" could not be run because of an IO error while launching the `sh`:\n{}", recipe, io_error),
+        });
+      },
     }
     Ok(())
   }
diff --git a/src/tests.rs b/src/tests.rs
index 1ef2d85..fd3602f 100644
--- a/src/tests.rs
+++ b/src/tests.rs
@@ -1,3 +1,5 @@
+extern crate tempdir;
+
 use super::{ErrorKind, Justfile};
 
 fn expect_error(text: &str, line: usize, expected_error_kind: ErrorKind) {
@@ -130,3 +132,43 @@ fn first() {
   let justfile = expect_success("#hello\n#goodbye\na:\nb:\nc:\n");
   assert!(justfile.first().unwrap() == "a");
 }
+
+#[test]
+fn unknown_recipes() {
+  match expect_success("a:\nb:\nc:").run(&["a", "x", "y", "z"]).unwrap_err() {
+    super::RunError::UnknownRecipes{recipes} => assert_eq!(recipes, &["x", "y", "z"]),
+    other @ _ => panic!("expected an unknown recipe error, but got: {}", other),
+  }
+}
+
+#[test]
+fn code_error() {
+  match expect_success("fail:\n @function x { return 100; }; x").run(&["fail"]).unwrap_err() {
+    super::RunError::Code{recipe, code} => {
+      assert_eq!(recipe, "fail");
+      assert_eq!(code, 100);
+    },
+    other @ _ => panic!("expected an code run error, but got: {}", other),
+  }
+}
+
+#[test]
+fn run_order() {
+  let tmp = tempdir::TempDir::new("run_order").unwrap_or_else(|err| panic!("tmpdir: failed to create temporary directory: {}", err));
+  let path = tmp.path().to_str().unwrap_or_else(|| panic!("tmpdir: path was not valid UTF-8")).to_owned();
+  let text = r"
+a:
+  @touch a
+
+b: a
+  @mv a b
+
+c: b
+  @mv b c
+
+d: c
+  @rm c
+";
+  super::std::env::set_current_dir(path).expect("failed to set current directory");
+  expect_success(text).run(&["a", "d"]).unwrap();
+}