Solved bob in Bash

bash/bob/bob.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+#  matches any character that is not in the set of letters, digits, and question marks.
+cleaned="${1//[^a-zA-Z0-9\?]}"
+
+# all capitals and ending with ?
+if [[ "$cleaned" =~ ^[A-Z]+\?$ ]] ; then
+    echo "Calm down, I know what I'm doing!"
+# ending with ?
+elif [[ "$cleaned" =~ ^.*[a-z0-9]*.*\?$ ]] ; then
+    echo 'Sure.'
+# all capitals and not only digits
+elif [[ "$cleaned" =~ ^[A-Z0-9]+$ ]] && ! [[ "$cleaned" =~ ^[0-9]+$ ]] ; then
+    echo 'Whoa, chill out!'
+# if empty
+elif [[ -z "$cleaned" ]] ; then
+    echo 'Fine. Be that way!'
+else
+    echo 'Whatever.'
+fi