exclude ' from characters to ensure they can be used without escaping within single quotes

tools/rand_printable

@@ -5,7 +5,7 @@ function rand_printable() {
 	local TR="/usr/bin/tr"
 	local HEAD="/usr/bin/head"
 
-	${ECHO} -n "`</dev/urandom ${TR} -dc \ -~ | ${HEAD} -c${1:-512}`"
+	${ECHO} -n "`</dev/urandom ${TR} -dc \ -\&\(-~ | ${HEAD} -c${1:-512}`"
 }
 
 test "X$(basename -- "$0")" = "Xrand_printable" && rand_printable "$@"