Add --hold CLI flag

This implements --hold flag which keeps Alacritty open after
its child process exits.

Fixes #1165.

9 files changed, 130 insertions, 104 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index b48a10bc..e7a28413 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Bindings for ScrollToTop and ScrollToBottom actions
 - `ReceiveChar` key binding action to insert the key's text character
 - Live reload font size from config
+- New CLI flag `--hold` for keeping Alacritty opened after its child process exits
 
 ### Changed
 
diff --git a/alacritty/src/cli.rs b/alacritty/src/cli.rs
index aabcdee3..99387a61 100644
--- a/alacritty/src/cli.rs
+++ b/alacritty/src/cli.rs
@@ -35,6 +35,7 @@ pub struct Options {
     pub embed: Option<String>,
     pub log_level: LevelFilter,
     pub command: Option<Shell<'static>>,
+    pub hold: bool,
     pub working_dir: Option<PathBuf>,
     pub config: Option<PathBuf>,
     pub persistent_logging: bool,
@@ -53,6 +54,7 @@ impl Default for Options {
             embed: None,
             log_level: LevelFilter::Warn,
             command: None,
+            hold: false,
             working_dir: None,
             config: None,
             persistent_logging: false,
@@ -71,104 +73,106 @@ impl Options {
 
         let mut options = Options::default();
 
-        let matches =
-            App::new(crate_name!())
-                .version(version.as_str())
-                .author(crate_authors!("\n"))
-                .about(crate_description!())
-                .arg(Arg::with_name("ref-test").long("ref-test").help("Generates ref test"))
-                .arg(
-                    Arg::with_name("live-config-reload")
-                        .long("live-config-reload")
-                        .help("Enable automatic config reloading"),
-                )
-                .arg(
-                    Arg::with_name("no-live-config-reload")
-                        .long("no-live-config-reload")
-                        .help("Disable automatic config reloading")
-                        .conflicts_with("live-config-reload"),
-                )
-                .arg(
-                    Arg::with_name("print-events")
-                        .long("print-events")
-                        .help("Print all events to stdout"),
-                )
-                .arg(
-                    Arg::with_name("persistent-logging")
-                        .long("persistent-logging")
-                        .help("Keep the log file after quitting Alacritty"),
-                )
-                .arg(
-                    Arg::with_name("dimensions")
-                        .long("dimensions")
-                        .short("d")
-                        .value_names(&["columns", "lines"])
-                        .help(
-                            "Defines the window dimensions. Falls back to size specified by \
-                             window manager if set to 0x0 [default: 0x0]",
-                        ),
-                )
-                .arg(
-                    Arg::with_name("position")
-                        .long("position")
-                        .allow_hyphen_values(true)
-                        .value_names(&["x-pos", "y-pos"])
-                        .help(
-                            "Defines the window position. Falls back to position specified by \
-                             window manager if unset [default: unset]",
-                        ),
-                )
-                .arg(
-                    Arg::with_name("title")
-                        .long("title")
-                        .short("t")
-                        .takes_value(true)
-                        .help(&format!("Defines the window title [default: {}]", DEFAULT_NAME)),
-                )
-                .arg(
-                    Arg::with_name("class").long("class").takes_value(true).help(&format!(
-                        "Defines window class on Linux [default: {}]",
-                        DEFAULT_NAME
-                    )),
-                )
-                .arg(Arg::with_name("embed").long("embed").takes_value(true).help(
+        let matches = App::new(crate_name!())
+            .version(version.as_str())
+            .author(crate_authors!("\n"))
+            .about(crate_description!())
+            .arg(Arg::with_name("ref-test").long("ref-test").help("Generates ref test"))
+            .arg(
+                Arg::with_name("live-config-reload")
+                    .long("live-config-reload")
+                    .help("Enable automatic config reloading"),
+            )
+            .arg(
+                Arg::with_name("no-live-config-reload")
+                    .long("no-live-config-reload")
+                    .help("Disable automatic config reloading")
+                    .conflicts_with("live-config-reload"),
+            )
+            .arg(
+                Arg::with_name("print-events")
+                    .long("print-events")
+                    .help("Print all events to stdout"),
+            )
+            .arg(
+                Arg::with_name("persistent-logging")
+                    .long("persistent-logging")
+                    .help("Keep the log file after quitting Alacritty"),
+            )
+            .arg(
+                Arg::with_name("dimensions")
+                    .long("dimensions")
+                    .short("d")
+                    .value_names(&["columns", "lines"])
+                    .help(
+                        "Defines the window dimensions. Falls back to size specified by window \
+                         manager if set to 0x0 [default: 0x0]",
+                    ),
+            )
+            .arg(
+                Arg::with_name("position")
+                    .long("position")
+                    .allow_hyphen_values(true)
+                    .value_names(&["x-pos", "y-pos"])
+                    .help(
+                        "Defines the window position. Falls back to position specified by window \
+                         manager if unset [default: unset]",
+                    ),
+            )
+            .arg(
+                Arg::with_name("title")
+                    .long("title")
+                    .short("t")
+                    .takes_value(true)
+                    .help(&format!("Defines the window title [default: {}]", DEFAULT_NAME)),
+            )
+            .arg(
+                Arg::with_name("class")
+                    .long("class")
+                    .takes_value(true)
+                    .help(&format!("Defines window class on Linux [default: {}]", DEFAULT_NAME)),
+            )
+            .arg(
+                Arg::with_name("embed").long("embed").takes_value(true).help(
                     "Defines the X11 window ID (as a decimal integer) to embed Alacritty within",
-                ))
-                .arg(
-                    Arg::with_name("q")
-                        .short("q")
-                        .multiple(true)
-                        .conflicts_with("v")
-                        .help("Reduces the level of verbosity (the min level is -qq)"),
-                )
-                .arg(
-                    Arg::with_name("v")
-                        .short("v")
-                        .multiple(true)
-                        .conflicts_with("q")
-                        .help("Increases the level of verbosity (the max level is -vvv)"),
-                )
-                .arg(
-                    Arg::with_name("working-directory")
-                        .long("working-directory")
-                        .takes_value(true)
-                        .help("Start the shell in the specified working directory"),
-                )
-                .arg(Arg::with_name("config-file").long("config-file").takes_value(true).help(
-                    "Specify alternative configuration file [default: \
-                     $XDG_CONFIG_HOME/alacritty/alacritty.yml]",
-                ))
-                .arg(
-                    Arg::with_name("command")
-                        .long("command")
-                        .short("e")
-                        .multiple(true)
-                        .takes_value(true)
-                        .min_values(1)
-                        .allow_hyphen_values(true)
-                        .help("Command and args to execute (must be last argument)"),
-                )
-                .get_matches();
+                ),
+            )
+            .arg(
+                Arg::with_name("q")
+                    .short("q")
+                    .multiple(true)
+                    .conflicts_with("v")
+                    .help("Reduces the level of verbosity (the min level is -qq)"),
+            )
+            .arg(
+                Arg::with_name("v")
+                    .short("v")
+                    .multiple(true)
+                    .conflicts_with("q")
+                    .help("Increases the level of verbosity (the max level is -vvv)"),
+            )
+            .arg(
+                Arg::with_name("working-directory")
+                    .long("working-directory")
+                    .takes_value(true)
+                    .help("Start the shell in the specified working directory"),
+            )
+            .arg(Arg::with_name("config-file").long("config-file").takes_value(true).help(
+                "Specify alternative configuration file [default: \
+                 $XDG_CONFIG_HOME/alacritty/alacritty.yml]",
+            ))
+            .arg(
+                Arg::with_name("command")
+                    .long("command")
+                    .short("e")
+                    .multiple(true)
+                    .takes_value(true)
+                    .min_values(1)
+                    .allow_hyphen_values(true)
+                    .help("Command and args to execute (must be last argument)"),
+            )
+            .arg(Arg::with_name("hold").long("hold").help("Remain open after child process exits"))
+            .get_matches();
 
         if matches.is_present("ref-test") {
             options.ref_test = true;
@@ -238,6 +242,10 @@ impl Options {
             options.command = Some(Shell::new_with_args(command, args));
         }
 
+        if matches.is_present("hold") {
+            options.hold = true;
+        }
+
         options
     }
 
@@ -254,6 +262,8 @@ impl Options {
         );
         config.shell = self.command.or(config.shell);
 
+        config.hold = self.hold;
+
         config.window.dimensions = self.dimensions.unwrap_or(config.window.dimensions);
         config.window.position = self.position.or(config.window.position);
         config.window.title = self.title.or(config.window.title);
diff --git a/alacritty/src/main.rs b/alacritty/src/main.rs
index cbd00443..65e13a62 100644
--- a/alacritty/src/main.rs
+++ b/alacritty/src/main.rs
@@ -178,8 +178,7 @@ fn run(window_event_loop: GlutinEventLoop<Event>, config: Config) -> Result<(),
     // renderer and input processing. Note that access to the terminal state is
     // synchronized since the I/O loop updates the state, and the display
     // consumes it periodically.
-    let event_loop =
-        EventLoop::new(Arc::clone(&terminal), event_proxy.clone(), pty, config.debug.ref_test);
+    let event_loop = EventLoop::new(Arc::clone(&terminal), event_proxy.clone(), pty, &config);
 
     // The event loop channel allows write requests from the event processor
     // to be sent to the pty loop and ultimately written to the pty.
diff --git a/alacritty_terminal/src/config/mod.rs b/alacritty_terminal/src/config/mod.rs
index f810b519..26432415 100644
--- a/alacritty_terminal/src/config/mod.rs
+++ b/alacritty_terminal/src/config/mod.rs
@@ -130,6 +130,10 @@ pub struct Config<T> {
     #[serde(flatten)]
     pub ui_config: T,
 
+    /// Remain open after child process exits
+    #[serde(skip)]
+    pub hold: bool,
+
     // TODO: DEPRECATED
     #[serde(default, deserialize_with = "failure_default")]
     pub render_timer: Option<bool>,
diff --git a/alacritty_terminal/src/event_loop.rs b/alacritty_terminal/src/event_loop.rs
index ed78d79e..3e762840 100644
--- a/alacritty_terminal/src/event_loop.rs
+++ b/alacritty_terminal/src/event_loop.rs
@@ -13,6 +13,7 @@ use mio::{self, Events, PollOpt, Ready};
 use mio_extras::channel::{self, Receiver, Sender};
 
 use crate::ansi;
+use crate::config::Config;
 use crate::event::{self, Event, EventListener};
 use crate::sync::FairMutex;
 use crate::term::Term;
@@ -43,6 +44,7 @@ pub struct EventLoop<T: tty::EventedPty, U: EventListener> {
     tx: Sender<Msg>,
     terminal: Arc<FairMutex<Term<U>>>,
     event_proxy: U,
+    hold: bool,
     ref_test: bool,
 }
 
@@ -143,11 +145,11 @@ where
     U: EventListener + Send + 'static,
 {
     /// Create a new event loop
-    pub fn new(
+    pub fn new<V>(
         terminal: Arc<FairMutex<Term<U>>>,
         event_proxy: U,
         pty: T,
-        ref_test: bool,
+        config: &Config<V>,
     ) -> EventLoop<T, U> {
         let (tx, rx) = channel::channel();
         EventLoop {
@@ -157,7 +159,8 @@ where
             rx,
             terminal,
             event_proxy,
-            ref_test,
+            hold: config.hold,
+            ref_test: config.debug.ref_test,
         }
     }
 
@@ -327,7 +330,9 @@ where
                         #[cfg(unix)]
                         token if token == self.pty.child_event_token() => {
                             if let Some(tty::ChildEvent::Exited) = self.pty.next_child_event() {
-                                self.terminal.lock().exit();
+                                if !self.hold {
+                                    self.terminal.lock().exit();
+                                }
                                 self.event_proxy.send_event(Event::Wakeup);
                                 break 'event_loop;
                             }
diff --git a/extra/alacritty.man b/extra/alacritty.man
index fafb10c3..5f3bf3cb 100644
--- a/extra/alacritty.man
+++ b/extra/alacritty.man
@@ -14,6 +14,9 @@ However, it does allow configuration of many aspects of the terminal.
 \fB\-h\fR, \fB\-\-help\fR
 Prints help information
 .TP
+\fB\-\-hold\fR
+Remain open after child process exits
+.TP
 \fB\-\-live\-config\-reload\fR
 Enable automatic config reloading
 .TP
diff --git a/extra/completions/_alacritty b/extra/completions/_alacritty
index c2fb29c2..f074042f 100644
--- a/extra/completions/_alacritty
+++ b/extra/completions/_alacritty
@@ -11,6 +11,7 @@ _arguments \
   "--print-events[print all events to stdout]" \
   '(-v)'{-q,-qq}"[reduce the level of verbosity (min is -qq)]" \
   "--ref-test[generate ref test]" \
+  "--hold[remain open after child process exits]" \
   '(-q)'{-v,-vv,-vvv}"[increase the level of verbosity (max is -vvv)]" \
   "$ign(-)"{-V,--version}"[print version information]" \
   "--class=[define the window class]:class" \
diff --git a/extra/completions/alacritty.bash b/extra/completions/alacritty.bash
index d87dd215..d2abda7e 100644
--- a/extra/completions/alacritty.bash
+++ b/extra/completions/alacritty.bash
@@ -11,7 +11,7 @@ _alacritty()
     cur="${COMP_WORDS[COMP_CWORD]}"
     prev="${COMP_WORDS[COMP_CWORD-1]}"
     prevprev="${COMP_WORDS[COMP_CWORD-2]}"
-    opts="-h --help -V --version --live-config-reload --no-live-config-reload --persistent-logging --print-events -q -qq -v -vv -vvv --ref-test -e --command --config-file -d --dimensions --position -t --title --embed --class --working-directory"
+    opts="-h --help -V --version --live-config-reload --no-live-config-reload --persistent-logging --print-events -q -qq -v -vv -vvv --ref-test --hold -e --command --config-file -d --dimensions --position -t --title --embed --class --working-directory"
 
     # If `--command` or `-e` is used, stop completing
     for i in "${!COMP_WORDS[@]}"; do
diff --git a/extra/completions/alacritty.fish b/extra/completions/alacritty.fish
index 3daa3447..4fb662d3 100644
--- a/extra/completions/alacritty.fish
+++ b/extra/completions/alacritty.fish
@@ -37,6 +37,9 @@ complete -c alacritty \
   -a '(__fish_complete_directories (commandline -ct))' \
   -l "working-directory" \
   -d "Start shell in specified directory"
+complete -c alacritty \
+  -l "hold" \
+  -d "Remain open after child process exits"
 
 # Output
 complete \