gawk: POSIX

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1 A.3 Changes Between SVR4 and POSIX 'awk'
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1 The POSIX Command Language and Utilities standard for 'awk' (1992)
1 introduced the following changes into the language:
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1      Options::)
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1    * The use of 'CONVFMT' for controlling the conversion of numbers to
1      strings (⇒Conversion)
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1    * The concept of a numeric string and tighter comparison rules to go
1      with it (⇒Typing and Comparison)
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1    * The use of predefined variables as function parameter names is
1      forbidden (⇒Definition Syntax)
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1    * More complete documentation of many of the previously undocumented
1      features of the language
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1    In 2012, a number of extensions that had been commonly available for
1 many years were finally added to POSIX. They are:
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1    * The 'fflush()' built-in function for flushing buffered output
1      (⇒I/O Functions)
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1    * The 'nextfile' statement (⇒Nextfile Statement)
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1    * The ability to delete all of an array at once with 'delete ARRAY'
1      (⇒Delete)
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1    ⇒Common Extensions for a list of common extensions not
1 permitted by the POSIX standard.
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1    The 2008 POSIX standard can be found online at
1 <http://pubs.opengroup.org/onlinepubs/9699919799/>.
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