connect default

src/errors.rs

@@ -31,6 +31,9 @@ pub enum Error {
   #[error("nul error: {0}")]
   Nul(#[from] std::ffi::NulError),
 
+  #[error("env var error: {0}")]
+  Var(#[from] std::env::VarError),
+
   #[error("error")]
   Error,
 }

src/xlib/display.rs

@@ -1,7 +1,7 @@
 use std::ffi::CString;
 use std::mem::MaybeUninit;
 use std::os::raw::c_char;
-use std::ptr;
+use std::{ptr, env};
 
 use x11::xlib;
 
@@ -43,6 +43,11 @@ impl Display {
     Ok(Display { inner })
   }
 
+  pub fn connect_default() -> Result<Display> {
+    let env = env::var("DISPLAY")?;
+    Self::connect(env)
+  }
+
   /// Create a Display for an existing connection
   pub fn from_handle(handle: u64) -> Self {
     Display {