17.4.15 Changes From Version 1 of the API

The current API is not binary compatible with version 1 of the API. You will have to recompile your extensions in order to use them with the current version of gawk.

Fortunately, at the possible expense of some compile-time warnings, the API remains source-code–compatible with the previous API. The major differences are the additional members in the awk_ext_func_t structure, and the addition of the third argument to the C implementation function (see section Registering An Extension Function).

Here is a list of individual features that changed from version 1 to version 2 of the API:

• Numeric values can now have MPFR/MPZ variants (see section General-Purpose Data Types).
• There are new string types: AWK_REGEX and AWK_STRNUM (see section General-Purpose Data Types).
• The ezalloc() macro is new (see section Memory Allocation Functions and Convenience Macros).
• The awk_ext_func_t structure changed. Instead of num_expected_args, it now has max_expected and min_required (see section Registering An Extension Function).
• For get_record(), an input parser can now specify field widths (see section Customized Input Parsers).
• Extensions can now produce nonfatal error messages (see section Printing Messages).
• When flattening an array, you can now specify the index and value types (see section Array Functions).
• The get_file() API is new (see section Accessing and Manipulating Redirections).