diff --git a/.todo.md b/.todo.md
index 6ae6d03..4f4896c 100644
--- a/.todo.md
+++ b/.todo.md
@@ -1,9 +1,11 @@
 - [ ] 0.3.2
-  - [ ] Better CLI
-    - [ ] Allow providing syntax highlighting option
-    - [X] Allow providing config file
-- [ ] 0.3.3
-  - [ ] Help page inside editor
+  - [ ] Command line
+    - [ ] Help message
+    - [X] Switch to read only mode
+      - [X] No saving
+      - [X] No exe
+    - [X] Switch syntax highlighting mode
+  - [X] Allow providing config file
 - [ ] UPDATE AUR PACKAGE
 - [ ] Better documentation (particularly around config file)
 - [X] 0.3.1 - various fixes
@@ -27,5 +29,3 @@
 - [ ] More plugins - 0.4.2
   - [ ] Bracket and Quote Pairs
   - [ ] Auto indentation
-- [ ] Tweaks - 0.4.3
-  - [ ] Read only mode
diff --git a/Cargo.lock b/Cargo.lock
index 6d42ac9..13a6abe 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -150,9 +150,9 @@ checksum = "b9d38e5712e29fb0c2caeb33b1803c8feade6e3380c7a92788fb219999b2849e"
 
 [[package]]
 name = "kaolinite"
-version = "0.8.0"
+version = "0.8.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa23d0ca201d2a2b921752b47756831936abddf75e5f3c365a7ba45ac4736152"
+checksum = "75e99c129d29095bc179446426f0ca274c9cb2654b6aeed3533f16fd7f433b34"
 dependencies = [
  "quick-error",
  "regex",
diff --git a/Cargo.toml b/Cargo.toml
index bcd5211..b62a011 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,7 +28,7 @@ codegen-units = 1
 alinio = "0.2.1"
 crossterm = "0.27.0"
 jargon-args = "0.2.7"
-kaolinite = "0.8.0"
+kaolinite = "0.8.1"
 mlua = { version = "0.9.9", features = ["lua54", "vendored"] }
 quick-error = "2.0.1"
 shellexpand = "3.1.0"
diff --git a/config/.oxrc b/config/.oxrc
index deb7426..20561c9 100644
--- a/config/.oxrc
+++ b/config/.oxrc
@@ -52,6 +52,7 @@ Ctrl + Y:   Redo
 Ctrl + F:   Find        
 Ctrl + R:   Replace     
 Ctrl + D:   Delete Line 
+Ctrl + K:   Command Line
 Shift + ->: Next Tab    
 Shift + <-: Previous Tab
 {highlight_end}
diff --git a/src/cli.rs b/src/cli.rs
index a462045..2ca4c8f 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -10,14 +10,19 @@ Ox: A lightweight and flexible text editor
 USAGE: ox [options] [files]
 
 OPTIONS:
-    --help, -h                 : Show this help message
-    --version, -v              : Show the version number
-    --config [path], -c [path] : Specify the configuration file
+  --help, -h                 : Show this help message
+  --version, -v              : Show the version number
+  --config [path], -c [path] : Specify the configuration file
+  --readonly, -r             : Prevent opened files from writing
+  --filetype [ext], -f [ext] : Set the file type of files opened
 
 EXAMPLES:
-    ox test.txt
-    ox test.txt test2.txt
-    ox /home/user/docs/test.txt
+  ox
+  ox test.txt
+  ox test.txt test2.txt
+  ox /home/user/docs/test.txt
+  ox -c config.lua test.txt
+  ox -r -c ~/.config/.oxrc -f lua my_file.lua\
 ";
 
 /// Struct to help with starting ox
@@ -45,11 +50,21 @@ impl CommandLineInterface {
         self.jargon.contains(["-v", "--version"])
     }
 
+    /// Determine if the user wishes to open files in read only
+    pub fn read_only(&mut self) -> bool {
+        self.jargon.contains(["-r", "--readonly"])
+    }
+
     /// Get all the files the user has requested
     pub fn get_files(&mut self) {
         self.to_open = self.jargon.clone().finish();
     }
 
+    /// Get file types
+    pub fn get_file_type(&mut self) -> Option<String> {
+        let filetype_key: Key = ["-f", "--filetype"].into();
+        self.jargon.option_arg::<String, Key>(filetype_key.clone())
+    }
     /// Configuration file path
     pub fn get_config_path(&mut self) -> String {
         let config_key: Key = ["-c", "--config"].into();
diff --git a/src/editor.rs b/src/editor.rs
index 4e69221..77cdc91 100644
--- a/src/editor.rs
+++ b/src/editor.rs
@@ -112,6 +112,22 @@ impl Editor {
         }
     }
 
+    pub fn set_readonly(&mut self, idx: usize) -> Result<()> {
+        if let Some(doc) = self.doc.get_mut(idx) {
+            doc.read_only = true;
+        }
+        Ok(())
+    }
+
+    /// Set the highlighter of a document
+    pub fn set_highlighter(&mut self, mut highlighter: Highlighter, idx: usize) -> Result<()> {
+        if let Some(doc) = self.doc.get_mut(idx) {
+            highlighter.run(&doc.lines);
+            self.highlighter[idx] = highlighter;
+        }
+        Ok(())
+    }
+
     /// Gets a reference to the current document
     pub fn doc(&self) -> &Document {
         self.doc.get(self.ptr).unwrap()
@@ -183,6 +199,8 @@ impl Editor {
                     (KMod::NONE, KCode::Delete) => self.delete()?,
                     (KMod::NONE, KCode::Enter) => self.enter()?,
                     (KMod::CONTROL, KCode::Char('d')) => self.delete_line()?,
+                    // Command
+                    (KMod::CONTROL, KCode::Char('k')) => self.command()?,
                     _ => (),
                 },
                 CEvent::Resize(w, h) => {
@@ -766,4 +784,28 @@ impl Editor {
         self.terminal.show_cursor()?;
         Ok(result)
     }
+
+    /// Open command line
+    pub fn command(&mut self) -> Result<()> {
+        let cmd = self.prompt("Command")?;
+        self.run_command(cmd)?;
+        Ok(())
+    }
+
+    /// Run a command
+    pub fn run_command(&mut self, cmd: String) -> Result<()> {
+        match cmd.split(' ').collect::<Vec<&str>>().as_slice() {
+            ["filetype", ext] => {
+                // Change the highlighter of the current file
+                self.highlighter[self.ptr] = from_extension(ext, 4)
+                    .unwrap_or_else(|| Highlighter::new(4));
+            }
+            ["readonly", "true"] => self.doc_mut().read_only = true,
+            ["readonly", "false"] => self.doc_mut().read_only = false,
+            _ => {
+                self.feedback = Feedback::Error(format!("Command '{}' not found", cmd));
+            }
+        }
+        Ok(())
+    }
 }
diff --git a/src/error.rs b/src/error.rs
index 0ce332e..8b95e35 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -14,6 +14,7 @@ quick_error! {
                 match err {
                     KError::NoFileName => "This document has no file name, please use 'save as' instead".to_string(),
                     KError::OutOfRange => "Requested operation is out of range".to_string(),
+                    KError::ReadOnlyFile => "This file is read only and can't be saved or edited".to_string(),
                     KError::Rope(rerr) => format!("Backend had an issue processing text: {rerr}"),
                     KError::Io(ioerr) => format!("I/O Error: {ioerr}"),
                 }
diff --git a/src/main.rs b/src/main.rs
index 3753216..3cf5413 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -4,6 +4,7 @@ mod error;
 mod cli;
 mod ui;
 
+use synoptic::{Highlighter, from_extension};
 use error::Result;
 use cli::CommandLineInterface;
 use editor::Editor;
@@ -25,12 +26,25 @@ fn main() {
 }
 
 fn run(mut cli: CommandLineInterface) -> Result<()> {
+    let read_only = cli.read_only();
     let config_path = cli.get_config_path();
+    let file_type = cli.get_file_type();
     cli.get_files();
     // Create editor and open requested files
     let mut editor = Editor::new(config_path)?;
-    for file in cli.to_open {
-        editor.open_or_new(file)?;
+    for (c, file) in cli.to_open.iter().enumerate() {
+        // Open the file
+        editor.open_or_new(file.to_string())?;
+        // Set read only if applicable
+        if read_only {
+            editor.set_readonly(c)?;
+        }
+        // Set highlighter if applicable
+        if let Some(ref ext) = file_type {
+            let highlighter = from_extension(&ext, 4)
+                .unwrap_or_else(|| Highlighter::new(4));
+            editor.set_highlighter(highlighter, c)?;
+        }
     }
 
     // Run the editor and handle errors if applicable