add --daemonize flag

Cargo.toml

@@ -55,6 +55,7 @@ zstd = "0.4"
 [target.'cfg(unix)'.dependencies]
 mio = "0.6"
 mio-extras = "2.0"
+daemonize = "0.4"
 
 [dependencies.fontconfig]
 optional = true

src/config.rs

@@ -118,6 +118,9 @@ pub struct Config {
 
     #[serde(default)]
     pub keys: Vec<Key>,
+
+    #[serde(default)]
+    pub daemon_options: DaemonOptions,
 }
 
 #[derive(Debug, Deserialize, Clone)]
@@ -362,6 +365,36 @@ fn default_dpi() -> f64 {
     96.0
 }
 
+#[derive(Default, Debug, Clone, Deserialize)]
+pub struct DaemonOptions {
+    pub pid_file: Option<PathBuf>,
+    pub stdout: Option<PathBuf>,
+    pub stderr: Option<PathBuf>,
+}
+
+impl DaemonOptions {
+    pub fn pid_file(&self) -> PathBuf {
+        self.pid_file
+            .as_ref()
+            .cloned()
+            .unwrap_or_else(|| RUNTIME_DIR.join("pid"))
+    }
+
+    pub fn stdout(&self) -> PathBuf {
+        self.stdout
+            .as_ref()
+            .cloned()
+            .unwrap_or_else(|| RUNTIME_DIR.join("log"))
+    }
+
+    pub fn stderr(&self) -> PathBuf {
+        self.stderr
+            .as_ref()
+            .cloned()
+            .unwrap_or_else(|| RUNTIME_DIR.join("log"))
+    }
+}
+
 /// Configures an instance of a multiplexer that can be communicated
 /// with via a unix domain socket
 #[derive(Default, Debug, Clone, Deserialize)]
@@ -483,6 +516,7 @@ impl Default for Config {
             keys: vec![],
             tls_servers: vec![],
             tls_clients: vec![],
+            daemon_options: Default::default(),
         }
     }
 }

src/main.rs

@@ -98,6 +98,10 @@ struct StartCommand {
     #[structopt(long = "no-auto-connect")]
     no_auto_connect: bool,
 
+    /// Detach from the foreground and become a background process
+    #[structopt(long = "daemonize")]
+    daemonize: bool,
+
     /// Instead of executing your shell, run PROG.
     /// For example: `wezterm start -- bash -l` will spawn bash
     /// as if it were a login shell.
@@ -129,7 +133,23 @@ enum CliSubCommand {
     List,
 }
 
-fn run_terminal_gui(config: Arc<config::Config>, opts: &StartCommand) -> Result<(), Error> {
+fn run_terminal_gui(config: Arc<config::Config>, opts: &StartCommand) -> Fallible<()> {
+    #[cfg(unix)]
+    {
+        if opts.daemonize {
+            use std::fs::OpenOptions;
+            let mut options = OpenOptions::new();
+            options.write(true).create(true).append(true);
+            let stdout = options.open(config.daemon_options.stdout())?;
+            let stderr = options.open(config.daemon_options.stderr())?;
+            daemonize::Daemonize::new()
+                .stdout(stdout)
+                .stderr(stderr)
+                .pid_file(config.daemon_options.pid_file())
+                .start()?;
+        }
+    }
+
     let font_system = opts.font_system.unwrap_or(config.font_system);
     font_system.set_default();