Add Bash script for creating windows on i3 startup

There's still an issue with starting screen in detached mode (with
`screen -d -m`) and starting xterms that immediately attach (like the
script does) on my system: backspace and ^H misbehave and erase all
characters before the cursor in those xterms.

config/i3/config

@@ -154,9 +154,6 @@ gaps outer -22
 smart_gaps on
 # }}}1
 
-exec --no-startup-id "i3-msg 'append_layout ~/.config/i3/scratchpad.json; move scratchpad'"
-exec --no-startup-id "xterm -e 'screen -x || screen'"
-exec --no-startup-id "i3-msg 'append_layout ~/.config/i3/workspace-2.json; move workspace 2'"
-exec --no-startup-id "xterm -e 'screen -x'"
+exec --no-startup-id ~/dotfiles/config/i3/startup.sh
 
 # vim: tw=90 sts=-1 sw=3 et fdm=marker

config/i3/startup.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+i3-msg 'append_layout ~/.config/i3/scratchpad.json; move scratchpad'
+i3-msg 'append_layout ~/.config/i3/workspace-2.json; move workspace 2'
+
+if ! screen -ls; then
+   # There's no screen session; create one.
+   screen -d -m
+   while ! screen -ls; do sleep .1; done
+   # Create some new windows inside the screen session.
+   screen -X screen && screen -X screen && screen -X 'select' 0
+fi
+
+# Disable XON/XOFF flow control before attaching.  I need to do this when the screen
+# session was started in detached mode and I'm starting a new xterm that immediately
+# attaches.  I don't understand why.
+# Note: using `screen -r` for one xterm if we just created a detached session doesn't
+# always work because either xterm may attach first (`screen -r` won't attach to a session
+# that is already attached somewhere else).  Contrary to what the screen(1) man page says,
+# `screen -x` still works when the screen session is detached.
+xterm -e 'stty -ixon && screen -x' &
+xterm -e 'stty -ixon && screen -x' &
+
+# vim: tw=90 sts=-1 sw=3 et