A.3 Changes Between SVR4 and POSIX awk

The POSIX Command Language and Utilities standard for awk (1992) introduced the following changes into the language:

In 2012, a number of extensions that had been commonly available for many years were finally added to POSIX. They are:

See Common Extensions Summary for a list of common extensions not permitted by the POSIX standard.

The 2018 POSIX standard can be found online at https://pubs.opengroup.org/onlinepubs/9699919799/.