scripts: imp requirements checking

scripts/install.sh

@@ -43,21 +43,20 @@ is_little_endian() {
 # machine.  The required software:
 #
 #   curl
-#   unzip (macOS)
-#   tar (linux)
+#   unzip (macOS) / tar (other unices)
 #
 check_required() {
-	readonly spec_darwin="unzip"
-	readonly spec_linux="tar"
+	readonly required_darwin="unzip"
+	readonly required_unix="tar"
 
 	# Split with space.
 	required="curl"
-	if [ "$os" = 'linux' ]
+	if [ "$os" = 'linux' ] || [ "$os" = 'freebsd' ]
 	then
-		required="$required $spec_linux"
+		required="$required $required_unix"
 	elif [ "$os" = 'darwin' ]
 	then
-		required="$required $spec_darwin"
+		required="$required $required_darwin"
 	fi
 
 	# Don't use quotes to get word splitting.