i3bar-protocol: add example (illustration-only!) shell script, clarify {"version":1} header

contrib/trivial-bar-script.sh

@@ -0,0 +1,29 @@
+#!/bin/sh
+# vim:ts=4:sw=4:expandtab
+# © 2012 Michael Stapelberg, Public Domain
+
+# This script is a trivial shell script to send your own output to i3bar while
+# using the JSON protocol.
+#
+# It is ugly and that is inherent to using JSON with shell scripts. You
+# _really_ should not do that. See i3status or i3status’s contrib/ directory
+# for examples of how to handle the output in higher-level languages.
+#
+# This example is purely for illustration of the protocol. DO NOT USE IT IN THE
+# REAL WORLD.
+
+# Send the header so that i3bar knows we want to use JSON:
+echo '{ "version": 1 }'
+
+# Begin the endless array.
+echo '['
+
+# We send an empty first array of blocks to make the loop simpler:
+echo '[]'
+
+# Now send blocks with information forever:
+while :;
+do
+	echo ",[{\"name\":\"time\",\"full_text\":\"$(date)\"}]"
+	sleep 1
+done