it would be a shame if we could not re-exec because we have filled the pipe

Signed-off-by: Mattias Andrée <maandree@operamail.com>
add xsnprintf macro

Signed-off-by: Mattias Andrée <maandree@operamail.com>
use more macros

Signed-off-by: Mattias Andrée <maandree@operamail.com>
use more macros

Signed-off-by: Mattias Andrée <maandree@operamail.com>