From a7d7000f592974031fe03b4c98a77cc6917cf877 Mon Sep 17 00:00:00 2001 From: Michael Kerrisk Date: Mon, 8 Feb 2016 12:12:14 +0100 Subject: [PATCH] feature_test_macros.7: Clarify relation between _XOPEN_SOURCE >=500 and _XOPEN_SOURCE_EXTENDED Emphasize that defining _XOPEN_SOURCE >=500 produces same effects as defining _XOPEN_SOURCE_EXTENDED. Signed-off-by: Michael Kerrisk --- man7/feature_test_macros.7 | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/man7/feature_test_macros.7 b/man7/feature_test_macros.7 index 29cf1d550..2893ee1c9 100644 --- a/man7/feature_test_macros.7 +++ b/man7/feature_test_macros.7 @@ -233,15 +233,21 @@ is defined with the value 200112L. is defined with the value 200809L. .RE .RE +.IP +In addition, defining +.BR _XOPEN_SOURCE +with a value of 500 or greater produces the same effects as defining +.BR _XOPEN_SOURCE_EXTENDED . .TP .B _XOPEN_SOURCE_EXTENDED If this macro is defined, and .B _XOPEN_SOURCE is defined, then expose definitions corresponding to the XPG4v2 (SUSv1) UNIX extensions (UNIX 95). -This macro is also implicitly defined if +Defining .B _XOPEN_SOURCE -is defined with a value of 500 or more. +with a value of 500 or more also produces the same effect as defining +.BR _XOPEN_SOURCE_EXTENDED . .TP .BR _ISOC99_SOURCE " (since glibc 2.1.3)" Exposes declarations consistent with the ISO C99 standard.