Add headless mode

This patch adds a daemon mode to Alacritty which allows starting the
Alacritty process without spawning an initial window.

While this does not provide any significant advantage over the existing
behavior of always spawning a window, it does integrate nicer with some
setups and is a pretty trivial addition.

1 files changed, 7 insertions, 2 deletions

diff --git a/alacritty/src/ipc.rs b/alacritty/src/ipc.rs
index d06d395e..3d14c4ce 100644
--- a/alacritty/src/ipc.rs
+++ b/alacritty/src/ipc.rs
@@ -20,13 +20,13 @@ const ALACRITTY_SOCKET_ENV: &str = "ALACRITTY_SOCKET";
 
 /// Create an IPC socket.
 pub fn spawn_ipc_socket(options: &Options, event_proxy: EventLoopProxy<Event>) -> Option<PathBuf> {
-    // Create the IPC socket and export its path as env variable if necessary.
+    // Create the IPC socket and export its path as env.
+
     let socket_path = options.socket.clone().unwrap_or_else(|| {
         let mut path = socket_dir();
         path.push(format!("{}-{}.sock", socket_prefix(), process::id()));
         path
     });
-    env::set_var(ALACRITTY_SOCKET_ENV, socket_path.as_os_str());
 
     let listener = match UnixListener::bind(&socket_path) {
         Ok(listener) => listener,
@@ -36,6 +36,11 @@ pub fn spawn_ipc_socket(options: &Options, event_proxy: EventLoopProxy<Event>) -
         },
     };
 
+    env::set_var(ALACRITTY_SOCKET_ENV, socket_path.as_os_str());
+    if options.daemon {
+        println!("ALACRITTY_SOCKET={}; export ALACRITTY_SOCKET", socket_path.display());
+    }
+
     // Spawn a thread to listen on the IPC socket.
     thread::spawn_named("socket listener", move || {
         let mut data = String::new();