Add wezterm.background_child_process

config/src/lua.rs

@@ -254,6 +254,10 @@ pub fn make_lua_context(config_file: &Path) -> anyhow::Result<Lua> {
             "run_child_process",
             lua.create_async_function(run_child_process)?,
         )?;
+        wezterm_mod.set(
+            "background_child_process",
+            lua.create_async_function(background_child_process)?,
+        )?;
         wezterm_mod.set("on", lua.create_function(register_event)?)?;
         wezterm_mod.set("emit", lua.create_async_function(emit_event)?)?;
         wezterm_mod.set("sleep_ms", lua.create_async_function(sleep_ms)?)?;
@@ -808,6 +812,26 @@ async fn run_child_process<'lua>(
     ))
 }
 
+async fn background_child_process<'lua>(_: &'lua Lua, args: Vec<String>) -> mlua::Result<()> {
+    let mut cmd = smol::process::Command::new(&args[0]);
+
+    if args.len() > 1 {
+        cmd.args(&args[1..]);
+    }
+
+    #[cfg(windows)]
+    {
+        use smol::process::windows::CommandExt;
+        cmd.creation_flags(winapi::um::winbase::CREATE_NO_WINDOW);
+    }
+
+    cmd.stdin(smol::process::Stdio::null())
+        .spawn()
+        .map_err(|e| mlua::Error::external(e))?;
+
+    Ok(())
+}
+
 fn permute_any_mods<'lua>(
     lua: &'lua Lua,
     item: mlua::Table,

docs/changelog.md

@@ -23,6 +23,7 @@ As features stabilize some brief notes about them will accumulate here.
 * `wezterm connect` now also supports the `--class` parameter to override the window class
 * [window_padding](config/lua/config/window_padding.md) now accepts values such as `"1cell"` or `"30%"` to compute values based on font or window metrics.
 * BSDish systems now support [toast notifications](https://github.com/wez/wezterm/issues/489)
+* [wezterm.background_child_process](config/lua/wezterm/background_child_process.md) function to spawn a process without waiting.
 
 #### Changed
 

docs/config/lua/wezterm/background_child_process.md

@@ -0,0 +1,34 @@
+# `wezterm.background_child_process(args)`
+
+*Since: nightly builds only*
+
+This function accepts an argument list; it will attempt to spawn that command
+in the background.
+
+May generate an error if the command is not able to be spawned (eg: perhaps
+the executable doesn't exist), but not all operating systems/environments
+report all types of spawn failures immediately upon spawn.
+
+This function doesn't return any value.
+
+This example shows how you might set up a custom key assignment that opens
+the terminal background image in a separate image viewer process:
+
+```lua
+local wezterm = require 'wezterm'
+
+return {
+  window_background_image = "/home/wez/Downloads/sunset-american-fork-canyon.jpg",
+  keys = {
+    {mods="CTRL|SHIFT", key="m",
+      action=wezterm.action_callback(function(win, pane)
+        wezterm.background_child_process(
+            {"xdg-open", win:effective_config().window_background_image})
+      end)
+    }
+  }
+}
+```
+
+See also [run_child_process](run_child_process.md)
+

docs/config/lua/wezterm/run_child_process.md

@@ -12,4 +12,4 @@ local wezterm = require 'wezterm';
 local success, stdout, stderr = wezterm.run_child_process({"ls", "-l"})
 ```
 
-
+See also [background_child_process](background_child_process.md)