diff --git a/src/main.rs b/src/main.rs
index 6e26dcb..fb04ae8 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,19 +1,20 @@
+use std::env;
 use std::fs;
-use std::path::PathBuf;
+use std::path::{Path, PathBuf};
 use std::process::exit;
 
 use anyhow::{Context, Result};
 use clap::Parser;
 use regex::Regex;
 
-use ::vmtest::{Ui, Vmtest};
+use ::vmtest::{Config, Target, Ui, Vmtest};
 
 #[derive(Parser, Debug)]
 #[clap(version)]
 struct Args {
     /// Path to config file
-    #[clap(short, long, default_value = "vmtest.toml")]
-    config: PathBuf,
+    #[clap(short, long)]
+    config: Option<PathBuf>,
     /// Filter by regex which targets to run
     ///
     /// This option takes a regular expression. If a target matches this regular
@@ -22,19 +23,54 @@ struct Args {
     /// Supported regex syntax: https://docs.rs/regex/latest/regex/#syntax.
     #[clap(short, long, default_value = ".*")]
     filter: String,
+    #[clap(short, long, conflicts_with = "config")]
+    kernel: Option<PathBuf>,
+    #[clap(conflicts_with = "config")]
+    command: Vec<String>,
+}
+
+/// Configure a `Vmtest` instance from command line arguments.
+fn config(args: &Args) -> Result<Vmtest> {
+    if let Some(kernel) = &args.kernel {
+        let cwd = env::current_dir().context("Failed to get current directory")?;
+        let config = Config {
+            target: vec![Target {
+                name: kernel.file_name().unwrap().to_string_lossy().to_string(),
+                image: None,
+                uefi: false,
+                kernel: Some(kernel.clone()),
+                kernel_args: None,
+                command: args.command.join(" "),
+            }],
+        };
+
+        Vmtest::new(cwd, config)
+    } else {
+        let default = Path::new("vmtest.toml").to_owned();
+        let config_path = args.config.as_ref().unwrap_or(&default);
+        let contents = fs::read_to_string(config_path).context("Failed to read config file")?;
+        let config = toml::from_str(&contents).context("Failed to parse config")?;
+        let base = config_path.parent().unwrap();
+
+        Vmtest::new(base, config)
+    }
+}
+
+/// Whether or not to collapse command output in UI.
+///
+/// This is useful for one-liner invocations.
+fn show_cmd(args: &Args) -> bool {
+    args.config.is_none()
 }
 
 fn main() -> Result<()> {
     let args = Args::parse();
 
     env_logger::init();
-    let contents = fs::read_to_string(&args.config).context("Failed to read config file")?;
-    let config = toml::from_str(&contents).context("Failed to parse config")?;
-    let base = args.config.parent().unwrap();
-    let vmtest = Vmtest::new(base, config)?;
+    let vmtest = config(&args)?;
     let filter = Regex::new(&args.filter).context("Failed to compile regex")?;
     let ui = Ui::new(vmtest);
-    let failed = ui.run(&filter);
+    let failed = ui.run(&filter, show_cmd(&args));
     let rc = i32::from(failed != 0);
 
     exit(rc);
diff --git a/src/ui.rs b/src/ui.rs
index 6f444f6..ab0c09c 100644
--- a/src/ui.rs
+++ b/src/ui.rs
@@ -159,7 +159,7 @@ impl Ui {
     /// UI for a single target. Must be run on its own thread.
     ///
     /// Returns if the target was successful or not>
-    fn target_ui(updates: Receiver<Output>, target: String) -> bool {
+    fn target_ui(updates: Receiver<Output>, target: String, show_cmd: bool) -> bool {
         let term = Term::stdout();
         let mut stage = Stage::new(term.clone(), &heading(&target, 1), None);
         let mut stages = 0;
@@ -201,21 +201,27 @@ impl Ui {
                     stages += 1;
                 }
                 Output::Command(s) => stage.print_line(s, None),
-                Output::CommandEnd(r) => match r {
-                    Ok(retval) => {
-                        if *retval != 0 {
-                            error_out_stage(
-                                &mut stage,
-                                &anyhow!("Command failed with exit code: {}", retval),
-                            );
+                Output::CommandEnd(r) => {
+                    if show_cmd {
+                        stage.expand(true);
+                    }
+
+                    match r {
+                        Ok(retval) => {
+                            if *retval != 0 {
+                                error_out_stage(
+                                    &mut stage,
+                                    &anyhow!("Command failed with exit code: {}", retval),
+                                );
+                                errors += 1;
+                            }
+                        }
+                        Err(e) => {
+                            error_out_stage(&mut stage, e);
                             errors += 1;
                         }
-                    }
-                    Err(e) => {
-                        error_out_stage(&mut stage, e);
-                        errors += 1;
-                    }
-                },
+                    };
+                }
             }
         }
 
@@ -223,10 +229,10 @@ impl Ui {
         drop(stage);
 
         // Only clear target stages if target was successful
-        if errors == 0 {
+        if errors == 0 && !show_cmd {
             clear_last_lines(&term, stages);
             term.write_line("PASS").expect("Failed to write terminal");
-        } else {
+        } else if !show_cmd {
             term.write_line("FAILED").expect("Failed to write terminal");
         }
 
@@ -235,10 +241,13 @@ impl Ui {
 
     /// Run all the targets in the provided `vmtest`
     ///
+    /// `filter` specifies the regex to filter targets by.
+    /// `show_cmd` specifies if the command output should always be shown.
+    ///
     /// Note this function is "infallible" b/c on error it will display
     /// the appropriate error message to screen. Rather, it returns how
     /// many targets failed.
-    pub fn run(self, filter: &Regex) -> usize {
+    pub fn run(self, filter: &Regex, show_cmd: bool) -> usize {
         let mut failed = 0;
         for (idx, target) in self
             .vmtest
@@ -251,7 +260,7 @@ impl Ui {
 
             // Start UI on its own thread b/c `Vmtest::run_one()` will block
             let name = target.name.clone();
-            let ui = thread::spawn(move || Self::target_ui(receiver, name));
+            let ui = thread::spawn(move || Self::target_ui(receiver, name, show_cmd));
 
             // Run a target
             self.vmtest.run_one(idx, sender);
diff --git a/tests/test.rs b/tests/test.rs
index c38b7f9..4f87909 100644
--- a/tests/test.rs
+++ b/tests/test.rs
@@ -86,7 +86,7 @@ fn assert_no_error(recv: Receiver<Output>) {
 fn test_run() {
     let vmtest = vmtest("vmtest.toml.allgood");
     let ui = Ui::new(vmtest);
-    let failed = ui.run(&*FILTER_ALL);
+    let failed = ui.run(&*FILTER_ALL, false);
     assert_eq!(failed, 0);
 }