C.16 Upgrading from 4.0 to 4.1
Upgrading to this version does not require any special efforts. You
can use your configuration files and filter scripts without any changes.
Notice only the following major differences between 4.1 and 4.0:
- Input files are preprocessed before compilation.
See Preprocessor, for more information.
- There is a way to discern between a not-supplied optional
parameter, and a supplied one, having null value (see defined).
- The version 4.1 implements
sprintf function
(see String formatting) and printf macro
(see printf).
- Support for some obsolete features is withdrawn. These include:
- Using ‘&code’ to specify exception codes
- Pragma options:
retry, io-retry, and
connect-retry.