+# Check whether --with-hash-backup or --without-hash-backup was given.
+if test "${with_hash_backup+set}" = set; then
+ withval="$with_hash_backup"
+ :
+fi
+
+if test x"$with_hash_backup" != x -a x"$with_hash_backup" != x"no"; then
+ backup_prefix="#"
+else
+ backup_prefix=","
+fi
+cat >> confdefs.h <<EOF
+#define BACKUP_PREFIX "$backup_prefix"
+EOF
+