diff --git a/src/app/app.rs b/src/app/app.rs
index 7f0e752..973c139 100644
--- a/src/app/app.rs
+++ b/src/app/app.rs
@@ -1,4 +1,4 @@
-use std::{io, path::PathBuf};
+use std::{collections::HashMap, io, path::PathBuf};
 
 use ratatui::{
     DefaultTerminal, Frame,
@@ -21,14 +21,28 @@ pub struct App {
     pub mode: Mode,
     pub file: Option<PathBuf>,
     pub error_msg: ErrorMessage,
+    pub vars: HashMap<String, String>,
 }
 
 impl Widget for &App {
     fn render(self, area: prelude::Rect, buf: &mut prelude::Buffer) {
         let len = LEN as u16;
 
-        let cell_height = 1;
-        let cell_length = 10;
+        let mut cell_height = 1;
+        let mut cell_length = 10;
+
+        if let Some(h) = self.vars.get("height") {
+            if let Ok(p) = h.parse::<u16>() {
+                cell_height = p;
+            }
+        }
+        if let Some(l) = self.vars.get("length") {
+            if let Ok(p) = l.parse::<u16>() {
+                cell_length = p;
+            }
+        }
+
+
 
         let x_max = if area.width / cell_length > len { len - 1 } else { area.width / cell_length };
         let y_max = if area.height / cell_height > len { len - 1 } else { area.height / cell_height };
@@ -156,6 +170,7 @@ impl App {
             mode: Mode::Normal,
             file: None,
             error_msg: ErrorMessage::none(),
+            vars: HashMap::new(),
         }
     }
 
diff --git a/src/app/mode.rs b/src/app/mode.rs
index 7dd4cec..cc25830 100644
--- a/src/app/mode.rs
+++ b/src/app/mode.rs
@@ -64,7 +64,20 @@ impl Mode {
                 }
                 "q" => app.exit = true,
                 "set" => {
-                    // TODO solve issue #8
+                    if let Some(arg) = args.get(1) {
+                        let parts: Vec<&str> = arg.split('=').collect();
+                        if parts.len() != 2 {
+                            app.error_msg = ErrorMessage::new("set <key>=<value>");
+                            return;
+                        }
+                        let key = parts[0];
+                        let value = parts[1];
+
+                        app.vars.insert(key.to_owned(), value.to_owned());
+
+                    }
+                    app.error_msg = ErrorMessage::new("set <key>=<value>")
+
                 }
                 _ => {}
             }