POSIX Conformance

As per IEEE 1003.1-2017, this section details Zephyr’s POSIX conformance. See POSIX Options for per-option pages and POSIX Option Groups for bundled API groups.

POSIX System Interfaces

POSIX System Interfaces
Symbol	Support	Remarks
_POSIX_CHOWN_RESTRICTED	0
_POSIX_NO_TRUNC	0
_POSIX_VDISABLE	`'\0'`

POSIX System Interfaces
Symbol	Support	Remarks
_POSIX_VERSION	200809L
_POSIX_ASYNCHRONOUS_IO	200809L	`CONFIG_POSIX_ASYNCHRONOUS_IO`
_POSIX_BARRIERS	200809L	`CONFIG_POSIX_BARRIERS`
_POSIX_CLOCK_SELECTION	200809L	`CONFIG_POSIX_CLOCK_SELECTION`
_POSIX_MAPPED_FILES	200809L	`CONFIG_POSIX_MAPPED_FILES`
_POSIX_MEMORY_PROTECTION	200809L	`CONFIG_POSIX_MEMORY_PROTECTION` †
_POSIX_READER_WRITER_LOCKS	200809L	`CONFIG_POSIX_RW_LOCKS`
_POSIX_REALTIME_SIGNALS	200809L	`CONFIG_POSIX_REALTIME_SIGNALS`
_POSIX_SEMAPHORES	200809L	`CONFIG_POSIX_SEMAPHORES`
_POSIX_SPIN_LOCKS	200809L	`CONFIG_POSIX_SPIN_LOCKS`
_POSIX_THREAD_SAFE_FUNCTIONS	200809L	`CONFIG_POSIX_C_LANG_SUPPORT_R` or `CONFIG_POSIX_FILE_SYSTEM_R` or `CONFIG_POSIX_FILE_LOCKING` or `CONFIG_POSIX_SYSTEM_DATABASE_R`
_POSIX_THREADS	200809L	`CONFIG_POSIX_THREADS`
_POSIX_TIMEOUTS	200809L	`CONFIG_POSIX_TIMERS`
_POSIX_TIMERS	200809L	`CONFIG_POSIX_TIMERS`
_POSIX2_C_BIND	200809L

POSIX System Interfaces (Unsupported)
Symbol	Support	Remarks
_POSIX_JOB_CONTROL	-1	†
_POSIX_REGEXP	-1	†
_POSIX_SAVED_IDS	-1	†
_POSIX_SHELL	-1	†

POSIX System Interfaces (Optional)
Symbol	Support	Remarks
_POSIX_ADVISORY_INFO	-1
_POSIX_CPUTIME	200809L	`CONFIG_POSIX_CPUTIME`
_POSIX_DEVICE_CONTROL	-1
_POSIX_FSYNC	200809L	`CONFIG_POSIX_FSYNC`
_POSIX_IPV6	200809L	`CONFIG_POSIX_IPV6`
_POSIX_MEMLOCK	200809L	`CONFIG_POSIX_MEMLOCK` †
_POSIX_MEMLOCK_RANGE	200809L	`CONFIG_POSIX_MEMLOCK_RANGE`
_POSIX_MESSAGE_PASSING	200809L	`CONFIG_POSIX_MESSAGE_PASSING`
_POSIX_MONOTONIC_CLOCK	200809L	`CONFIG_POSIX_MONOTONIC_CLOCK`
_POSIX_PRIORITIZED_IO	200809L	`CONFIG_POSIX_PRIORITIZED_IO`
_POSIX_PRIORITY_SCHEDULING	200809L	`CONFIG_POSIX_PRIORITY_SCHEDULING`
_POSIX_RAW_SOCKETS	200809L	`CONFIG_POSIX_RAW_SOCKETS`
_POSIX_SHARED_MEMORY_OBJECTS	200809L	`CONFIG_POSIX_SHARED_MEMORY_OBJECTS`
_POSIX_SPAWN	200809L	`CONFIG_POSIX_SPAWN`
_POSIX_SPORADIC_SERVER	200809L	`CONFIG_POSIX_SPORADIC_SERVER` †
_POSIX_SYNCHRONIZED_IO	200809L	`CONFIG_POSIX_SYNCHRONIZED_IO`
_POSIX_THREAD_ATTR_STACKADDR	200809L	`CONFIG_POSIX_THREAD_ATTR_STACKADDR`
_POSIX_THREAD_ATTR_STACKSIZE	200809L	`CONFIG_POSIX_THREAD_ATTR_STACKSIZE`
_POSIX_THREAD_CPUTIME	200809L	`CONFIG_POSIX_CPUTIME`
_POSIX_THREAD_PRIO_INHERIT	200809L	`CONFIG_POSIX_THREAD_PRIO_INHERIT`
_POSIX_THREAD_PRIO_PROTECT	200809L	`CONFIG_POSIX_THREAD_PRIO_PROTECT`
_POSIX_THREAD_PRIORITY_SCHEDULING	200809L	`CONFIG_POSIX_THREAD_PRIORITY_SCHEDULING`
_POSIX_THREAD_PROCESS_SHARED	-1
_POSIX_THREAD_ROBUST_PRIO_INHERIT	-1
_POSIX_THREAD_ROBUST_PRIO_PROTECT	-1
_POSIX_THREAD_SPORADIC_SERVER	200809L	`CONFIG_POSIX_THREAD_SPORADIC_SERVER` †
_POSIX_TYPED_MEMORY_OBJECTS	-1
_XOPEN_CRYPT	-1
_XOPEN_REALTIME	700	`CONFIG_XSI_REALTIME`
_XOPEN_REALTIME_THREADS	700	`CONFIG_XSI_REALTIME_THREADS`
_XOPEN_STREAMS	200809L	`CONFIG_XSI_STREAMS`
_XOPEN_UNIX	700	`CONFIG_XSI`

Note

In Issue 7, _POSIX_MONOTONIC_CLOCK was an optional option. Issue 8 promoted it to a mandatory option alongside the other 200809L baseline interfaces.

POSIX Shell and Utilities

Zephyr does not support a POSIX shell or utilities at this time.

POSIX Shell and Utilities
Symbol	Support	Remarks
_POSIX2_C_DEV	-1	†
_POSIX2_CHAR_TERM	-1	†
_POSIX2_FORT_DEV	-1	†
_POSIX2_FORT_RUN	-1	†
_POSIX2_LOCALEDEF	-1	†
_POSIX2_PBS	-1	†
_POSIX2_PBS_ACCOUNTING	-1	†
_POSIX2_PBS_LOCATE	-1	†
_POSIX2_PBS_MESSAGE	-1	†
_POSIX2_PBS_TRACK	-1	†
_POSIX2_SW_DEV	-1	†
_POSIX2_UPE	-1	†
_POSIX2_UNIX	-1	†
_POSIX2_UUCP	-1	†

XSI Conformance

X/Open System Interfaces

X/Open System Interfaces
Symbol	Support	Remarks
_POSIX_FSYNC	200809L	`CONFIG_POSIX_FSYNC`
_POSIX_THREAD_ATTR_STACKADDR	200809L	`CONFIG_POSIX_THREAD_ATTR_STACKADDR`
_POSIX_THREAD_ATTR_STACKSIZE	200809L	`CONFIG_POSIX_THREAD_ATTR_STACKSIZE`
_POSIX_THREAD_PROCESS_SHARED	-1

Note

Some features may exhibit undefined behaviour as they fall beyond the scope of Zephyr’s current design and capabilities. For example, multiple users, regular expressions, and a conformant shell are features that are uncommon in low-footprint embedded systems. Other symbols are marked with the † (obelus) if they appeared in an earlier POSIX edition (for example IEEE 1003.13) but were later removed from the specification. Such undefined behaviour is denoted with the † (obelus) symbol. For implementation details and known deviations, please see Implementation Details.

Note

Features listed in various POSIX Options or Option Groups may be provided in whole or in part by a conformant C library implementation. This includes (but is not limited to) POSIX Extensions to the ISO C Standard (CX).