The file says/features.h defines the defaults for RTEMS. Some methods are not visible at the default standard level because they are extensions maybe GNU or BSD specific. The defaults are modified by the selection of the programming language standard and the feature macros your program defines. I recall that I'd you say std=c99, you lose visibility to a number of the POSIX methods.
This is the Linux man page on these. https://man7.org/linux/man-pages/man7/feature_test_macros.7.html Note that Linux and RTEMS do not agree on the default feature settings. My recollection is that RTEMS is closer to pure POSIX while Linux enables a number of non-POSIX extensions by default. You need to be careful to define any features you need early in case sys/features.h is implicitly included in your selection has no impact. --joel On Sun, Jan 3, 2021, 12:21 PM Sebastian Huber < sebastian.hu...@embedded-brains.de> wrote: > On 03/01/2021 18:06, Heinz Junkes wrote: > > > _XOPEN_SOURCE is not set anywhere in the RTEMS header files etc.. > > Yes, and this is how it should be. This define is supposed to be defined > by your application if necessary: > > https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html > > https://man7.org/linux/man-pages/man7/feature_test_macros.7.html > > -- > embedded brains GmbH > Herr Sebastian HUBER > Dornierstr. 4 > 82178 Puchheim > Germany > email: sebastian.hu...@embedded-brains.de > phone: +49-89-18 94 741 - 16 > fax: +49-89-18 94 741 - 08 > > Registergericht: Amtsgericht München > Registernummer: HRB 157899 > Vertretungsberechtigte Geschäftsführer: Peter Rasmussen, Thomas Dörfler > Unsere Datenschutzerklärung finden Sie hier: > https://embedded-brains.de/datenschutzerklaerung/ > > _______________________________________________ > devel mailing list > devel@rtems.org > http://lists.rtems.org/mailman/listinfo/devel
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