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	-1
_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	-1	†
_POSIX_SPORADIC_SERVER	-1	†
_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, multi-processing, ad-hoc memory-mapping, multiple users, or regular expressions are features that are uncommon in low-footprint embedded systems. Other symbols are marked with the † (obelus) when they appeared in an earlier POSIX edition (for example IEEE 1003.13) but were later removed from the specification and are not treated as current profile requirements in this documentation. Such undefined behaviour is denoted with the † (obelus) symbol. Additional details in POSIX Option Groups and POSIX Options.

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).