File: gawk.info,  Node: History summary,  Prev: Contributors,  Up: Language History

A.10 Summary
============

   * The 'awk' language has evolved over time.  The first release was
     with V7 Unix, circa 1978.  In 1987, for System V Release 3.1, major
     additions, including user-defined functions, were made to the
     language.  Additional changes were made for System V Release 4, in
     1989.  Since then, further minor changes have happened under the
     auspices of the POSIX standard.

   * Brian Kernighan's 'awk' provides a small number of extensions that
     are implemented in common with other versions of 'awk'.

   * 'gawk' provides a large number of extensions over POSIX 'awk'.
     They can be disabled with either the '--traditional' or '--posix'
     options.

   * The interaction of POSIX locales and regexp matching in 'gawk' has
     been confusing over the years.  Today, 'gawk' implements Rational
     Range Interpretation, where ranges of the form '[a-z]' match _only_
     the characters numerically between 'a' through 'z' in the machine's
     native character set.  Usually this is ASCII, but it can be EBCDIC
     on IBM S/390 systems.

   * Many people have contributed to 'gawk' development over the years.
     We hope that the list provided in this major node is complete and
     gives the appropriate credit where credit is due.