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1  Copyright (C) 1992, 1995, 1998, 2001, 2006, 2007, 2010, 2011, 2015, 20192  Free Software Foundation, Inc.3  4  Copying and distribution of this file, with or without modification,5  are permitted in any medium without royalty provided the copyright6  notice and this notice are preserved.7--------------------------------------------------------------------------8Sun Apr 21 14:27:19 IDT 20199============================10This file documents several things related to the 2008 POSIX standard11that I noted after reviewing it.12 131. POSIX leaves undefined what happens for something like14 15	awk '{ print ; exit }' if=42 /etc/passwd16 17   Mawk diagnoses this.  Gawk and BWK awk do not. This doesn't seem to be18   worth the effort to add the code, but at least I'm aware of it.19 202. The 2001-2004 standards accidentally required support for hexadecimal21   floating point constants and for Infinity and Not-A-Number (NaN) values.22 23   The 2008 standard now explicitly allows, but does not require, such24   support.25 26   More discussion is provided in the node `POSIX Floating Point Problems'27   in gawk.texi.28 293. String comparison with <, <= etc is supposed to take the locale's collating30   sequence into account.  By default gawk doesn't do this. Rather, gawk31   will do this only if --posix is in effect.32 334. According to POSIX, the function parameters of one function may not have34   the same name as another function, making this invalid:35 36	function foo() { ... }37	function bar(foo) { ...}38 39   Or even:40 41	function bar(foo) { ...}42	function foo() { ... }43 44   Gawk enforces this only with --posix.45 465. According to POSIX (following the A, K, & W book), when RS = "", then47   newline is also a separator, "no matter what the value of FS is", implying48   that this is true even if FS is a regexp.49 50   In fact, UNIX awk has never behaved that, way; it adds \n to the list51   for FS = " " or any other single character, and gawk does too. This is52   essentially a bug in POSIX.53 54The following things aren't described by POSIX but ought to be:55 561. The value of $0 in an END rule57 582. The return value of a function that either does return with no value59   or that falls off the end of the function body.60 613. What happens with substr() if start is <= 0, or greater than the length62   of the string, or if length is <= 0.63 644. Whether "next" can be invoked from a function body.65