From cdbb5fe7006a42b9ae92254b8ddbb6a31b942eb1 Mon Sep 17 00:00:00 2001
From: Koichi Murase <myoga.murase@gmail.com>
Date: Wed, 17 Jul 2024 13:27:59 +0900
Subject: [PATCH] Check Bash version

---
 mcfly.bash | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/mcfly.bash b/mcfly.bash
index 87d26c2..8e20a96 100644
--- a/mcfly.bash
+++ b/mcfly.bash
@@ -1,6 +1,13 @@
 #!/bin/bash
 
 function mcfly_initialize {
+  # Note: We avoid using [[ ... ]] to check the Bash version because we are
+  # even unsure whether it is available before confirming the Bash version.
+  if [ -z "${BASH_VERSINFO-}" ] || [ "${BASH_VERSINFO-}" -lt 3 ]; then
+    printf 'mcfly.bash: This setup requires Bash >= 3.0.' >&2
+    return 1
+  fi
+
   unset -f "${FUNCNAME[0]}"
 
   # Ensure stdin is a tty