awklanguage 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.
awkprovides a small number of extensions that are implemented in common with other versions of
gawkprovides a large number of extensions over POSIX
awk. They can be disabled with either the
gawkhas been confusing over the years. Today,
gawkimplements 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.
gawkdevelopment over the years. We hope that the list provided in this chapter is complete and gives the appropriate credit where credit is due.