diff --git a/Cargo.lock b/Cargo.lock
index dfa4698..d7881b5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2,12 +2,42 @@
 # It is not intended for manual editing.
 version = 3
 
+[[package]]
+name = "aho-corasick"
+version = "1.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ea5d730647d4fadd988536d06fecce94b7b4f2a7efdae548f1cf4b63205518ab"
+dependencies = [
+ "memchr",
+]
+
+[[package]]
+name = "anstyle"
+version = "1.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7079075b41f533b8c61d2a4d073c4676e1f8b249ff94a393b0595db304e0dd87"
+
 [[package]]
 name = "anyhow"
 version = "1.0.68"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2cb2f989d18dd141ab8ae82f64d1a8cdd37e0840f73a406896cf5e99502fab61"
 
+[[package]]
+name = "assert_cmd"
+version = "2.0.12"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "88903cb14723e4d4003335bb7f8a14f27691649105346a0f0957466c096adfe6"
+dependencies = [
+ "anstyle",
+ "bstr",
+ "doc-comment",
+ "predicates",
+ "predicates-core",
+ "predicates-tree",
+ "wait-timeout",
+]
+
 [[package]]
 name = "autocfg"
 version = "1.1.0"
@@ -20,6 +50,17 @@ version = "1.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bef38d45163c2f1dde094a7dfd33ccf595c92905c8f8f4fdc18d06fb1037718a"
 
+[[package]]
+name = "bstr"
+version = "1.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4c2f7349907b712260e64b0afe2f84692af14a454be26187d9df565c7f69266a"
+dependencies = [
+ "memchr",
+ "regex-automata",
+ "serde",
+]
+
 [[package]]
 name = "cc"
 version = "1.0.79"
@@ -63,6 +104,24 @@ dependencies = [
  "os_str_bytes",
 ]
 
+[[package]]
+name = "difflib"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6184e33543162437515c2e2b48714794e37845ec9851711914eec9d308f6ebe8"
+
+[[package]]
+name = "doc-comment"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fea41bba32d969b513997752735605054bc0dfa92b4c56bf1189f2e174be7a10"
+
+[[package]]
+name = "either"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a26ae43d7bcc3b814de94796a5e736d4029efb0ee900c12e2d54c993ad1a1e07"
+
 [[package]]
 name = "errno"
 version = "0.2.8"
@@ -89,12 +148,23 @@ name = "fakemall"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "assert_cmd",
  "clap",
+ "predicates",
  "serde",
  "toml",
  "toml_edit",
 ]
 
+[[package]]
+name = "float-cmp"
+version = "0.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "98de4bbd547a563b716d8dfa9aad1cb19bfab00f4fa09a6a4ed21dbcf44ce9c4"
+dependencies = [
+ "num-traits",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.12.3"
@@ -148,6 +218,15 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "itertools"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b1c173a5686ce8bfa551b3563d0c2170bf24ca44da99c7ca4bfdab5418c3fe57"
+dependencies = [
+ "either",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.139"
@@ -162,9 +241,9 @@ checksum = "f051f77a7c8e6957c0696eac88f26b0117e54f52d3fc682ab19397a8812846a4"
 
 [[package]]
 name = "memchr"
-version = "2.5.0"
+version = "2.6.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2dffe52ecf27772e601905b7522cb4ef790d2cc203488bbd0e2fe85fcb74566d"
+checksum = "f665ee40bc4a3c5590afb1e9677db74a508659dfd71e126420da8274909a0167"
 
 [[package]]
 name = "nom8"
@@ -175,6 +254,21 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "normalize-line-endings"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "61807f77802ff30975e01f4f071c8ba10c022052f98b3294119f3e615d13e5be"
+
+[[package]]
+name = "num-traits"
+version = "0.2.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f30b0abd723be7e2ffca1272140fac1a2f084c77ec3e123c192b66af1ee9e6c2"
+dependencies = [
+ "autocfg",
+]
+
 [[package]]
 name = "once_cell"
 version = "1.17.0"
@@ -187,6 +281,37 @@ version = "6.4.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "9b7820b9daea5457c9f21c69448905d723fbd21136ccf521748f23fd49e723ee"
 
+[[package]]
+name = "predicates"
+version = "3.0.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "6dfc28575c2e3f19cb3c73b93af36460ae898d426eba6fc15b9bd2a5220758a0"
+dependencies = [
+ "anstyle",
+ "difflib",
+ "float-cmp",
+ "itertools",
+ "normalize-line-endings",
+ "predicates-core",
+ "regex",
+]
+
+[[package]]
+name = "predicates-core"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b794032607612e7abeb4db69adb4e33590fa6cf1149e95fd7cb00e634b92f174"
+
+[[package]]
+name = "predicates-tree"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "368ba315fb8c5052ab692e68a0eefec6ec57b23a36959c14496f0b0df2c0cecf"
+dependencies = [
+ "predicates-core",
+ "termtree",
+]
+
 [[package]]
 name = "proc-macro-error"
 version = "1.0.4"
@@ -229,6 +354,35 @@ dependencies = [
  "proc-macro2",
 ]
 
+[[package]]
+name = "regex"
+version = "1.9.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ebee201405406dbf528b8b672104ae6d6d63e6d118cb10e4d51abbc7b58044ff"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-automata",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-automata"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "59b23e92ee4318893fa3fe3e6fb365258efbfe6ac6ab30f090cdcbb7aa37efa9"
+dependencies = [
+ "aho-corasick",
+ "memchr",
+ "regex-syntax",
+]
+
+[[package]]
+name = "regex-syntax"
+version = "0.7.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "dbb5fb1acd8a1a18b3dd5be62d25485eb770e05afb408a9627d14d451bae12da"
+
 [[package]]
 name = "rustix"
 version = "0.36.7"
@@ -298,6 +452,12 @@ dependencies = [
  "winapi-util",
 ]
 
+[[package]]
+name = "termtree"
+version = "0.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3369f5ac52d5eb6ab48c6b4ffdc8efbcad6b89c765749064ba298f2c68a16a76"
+
 [[package]]
 name = "toml"
 version = "0.7.0"
@@ -344,6 +504,15 @@ version = "0.9.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 
+[[package]]
+name = "wait-timeout"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9f200f5b12eb75f8c1ed65abd4b2db8a6e1b138a20de009dacee265a2498f3f6"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
diff --git a/Cargo.toml b/Cargo.toml
index e44ee64..6d9eaed 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,11 +3,13 @@ name = "fakemall"
 version = "0.1.0"
 edition = "2021"
 
-# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
-
 [dependencies]
 clap = { version = "4.1.4", features = ["derive"] }
 toml_edit = "0.19.0"
 toml = "0.7.0"
 serde = { version = "1.0.152", features = ["derive"] }
-anyhow = "1.0.68"
\ No newline at end of file
+anyhow = "1.0.68"
+
+[dev-dependencies]
+assert_cmd = "2.0.12"
+predicates = "3.0.4"
diff --git a/src/main.rs b/src/main.rs
index c3e88ac..9189621 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -7,7 +7,7 @@ use std::{
     fs::{self, File},
     io::{Read, Write},
     os::unix::prelude::PermissionsExt,
-    path::{PathBuf},
+    path::PathBuf,
     process,
 };
 /// A simple tool for building fake command line interfaces
@@ -49,7 +49,7 @@ fn main() -> Result<()> {
 
     match &cli.command {
         Commands::Exec { set, command } => exec(set, command.trim()),
-        Commands::Save {.. } => todo!(),
+        Commands::Save { .. } => todo!(),
         Commands::Build { set, path } => build(set, path),
     }
 }
diff --git a/tests/cli.rs b/tests/cli.rs
new file mode 100644
index 0000000..bb78f6d
--- /dev/null
+++ b/tests/cli.rs
@@ -0,0 +1,41 @@
+use assert_cmd::prelude::*;
+use predicates::prelude::*;
+use std::process::Command;
+
+#[test]
+fn fakes_commands() -> Result<(), Box<dyn std::error::Error>> {
+    let mut cmd = Command::cargo_bin("fakemall")?;
+
+    cmd.arg("exec")
+        .arg("tests/test_config.toml")
+        .arg("dmidecode");
+    cmd.assert()
+        .success()
+        .stdout(predicate::str::contains("this is a sample output"));
+
+    Ok(())
+}
+
+#[test]
+fn set_doesnt_exist() -> Result<(), Box<dyn std::error::Error>> {
+    let mut cmd = Command::cargo_bin("fakemall")?;
+
+    cmd.arg("exec").arg("test/file/doesnt/exist").arg("kekw");
+    cmd.assert()
+        .failure()
+        .stderr(predicate::str::contains("No such file or directory"));
+
+    Ok(())
+}
+
+#[test]
+fn command_doesnt_exist() -> Result<(), Box<dyn std::error::Error>> {
+    let mut cmd = Command::cargo_bin("fakemall")?;
+
+    cmd.arg("exec").arg("tests/test_config.toml").arg("asdf");
+    cmd.assert()
+        .failure()
+        .stdout(predicate::str::contains("asdf: command not found"));
+
+    Ok(())
+}
diff --git a/tests/test_config.toml b/tests/test_config.toml
new file mode 100644
index 0000000..df4ac47
--- /dev/null
+++ b/tests/test_config.toml
@@ -0,0 +1,3 @@
+[[commands]]
+matches = "dmidecode"
+output = "this is a sample output"