feat: add segfault command

src/builtins/mod.rs

@@ -9,6 +9,7 @@ mod fetch;
 mod ls;
 mod open;
 mod pwd;
+mod segfault;
 
 pub struct BuiltinConfig {
     pub prompt_style: PromptStyle,
@@ -35,6 +36,7 @@ const BUILTINS: Lazy<Vec<(&str, Box<dyn Builtin>)>> = Lazy::new(|| {
         ("open", Box::new(open::Open)),
         ("fetch", Box::new(fetch::Fetch)),
         ("ls", Box::new(ls::Ls)),
+        ("segfault", Box::new(segfault::Segfault)),
     ]
 });
 

src/builtins/segfault.rs

@@ -0,0 +1,11 @@
+use crate::builtins::{Builtin, BuiltinConfig};
+use crate::error::ShellError;
+
+pub struct Segfault;
+
+impl Builtin for Segfault {
+    fn execute(&mut self, _: &mut BuiltinConfig, _: Vec<String>) -> Result<(), ShellError> {
+        unsafe { std::ptr::null_mut::<i32>().write(69) };
+        Ok(())
+    }
+}