This page helps rank how %%FreeBSD%% currently functions with certain opensource/UNIX standards, such as ISO C, POSIX, XSI, etc.

====== IEEE 1003.1-2001 ======

===== sys/time.h // time.h =====

| CLOCK_UPTIME .. CLOCK_SECOND | %%FreeBSD%% specific clocks/timers aren't properly hidden under __BSD_VISIBLE. |
| _POSIX_CPUTIME, et all | Not implemented, despite the fact that _POSIX_THREAD_CPUTIME is implemented. Gross oversight? |
| Incorrect includes | Some headers are including time.h and others are including sys/time.h by accident which has resulted in improper breakage in the sourcebase, based on the requirements in the stated in the %%FreeBSD%% and %%OpenGroup%% manpages. |

===== errno.h =====

| ENODATA | not implemented (XSI) |
| ENOSR | not implemented (XSI) |
| ENOSTR | not implemented (XSI) |
| ETIME | not implemented (XSI) |

===== sched.h =====

| SCHED_SPORADIC | not implemented |
| struct sched_param | not implemented |

===== stdlib.h =====

| realpath | non-conformant pieces ; see [3] |

===== unistd.h =====

| _SC_TIMERS / _SC_TIMER_MAX | value doesn't take into account offset of 3 used in sys/kern/kern_time.c used for `[timers] reserved for setitimer()'. |

====== POSIX 2008.1 ======

===== sys/kern/kern_time.c =====

| clockid_t | Many of the timer values are implemented as int, instead of clockid_t; being pedantic they should be defined as clockid_t (int32_t). |
| clock_getcpuclockid | not implemented |
| clock_nanosleep | not implemented; requires some kernel interfaces currently missing [2]. |
| clock_settime | kern_clock_settime does not return EINVAL for CLOCK_MONOTONIC. |
| itimerfix %%//%% itimespecfix | Is overloaded and unfortunately broken as it doesn't handle negative usec / nsec times. |
| timer_create | always returns EINVAL for CLOCK_THREAD_CPUTIME_ID due to definitions of MAX_CLOCKS; thus creating a timer for CLOCK_THREAD_CPUTIME_ID is completely impossible. |

===== limits.h =====

| PTHREAD_KEYS_MAX | Should be defined in limits.h, not pthread.h |
| PTHREAD_STACK_MIN | Should be defined in limits.h, not pthread.h |

===== mqueue.h =====

| mqd_t | Defined as a structure in %%FreeBSD%%. Is an integer in Linux. This means that code which assumes that mq_* APIs will return EBADF when provided a bad file descriptor (say -1) instead of segfaulting will get a nasty surprise. POSIX doesn't state what the underlying type has to be. |

====== XSI ======

===== signal.h =====

| SIGPOLL | not implemented |
| struct sig_param | not implemented |

===== time.h =====

| daylight | broken (both in %%FreeBSD%% and in POSIX); won't fix |
| getdate(3) | not implemented |
| timezone | broken (both in %%FreeBSD%% and in POSIX); won't fix |
| tzname | broken (both in %%FreeBSD%% and in POSIX); won't fix |

====== Under debate ======

The state of the following items is under debate:

===== signal.h =====

| SIGPOLL | XSI -- unsupported by choice for functional and security reasons |

====== References ======

  - http://lists.freebsd.org/pipermail/freebsd-standards/2010-April/001936.html
  - http://lists.freebsd.org/pipermail/freebsd-standards/2010-April/001948.html
  - https://bugs.freebsd.org/bugzilla/buglist.cgi?component=kern&short_desc=realpath&short_desc_type=allwordssubstr

====== Related Pages ======

  - C99 : https://man.freebsd.org/cgi/man.cgi?query=c99&sektion=7
  - SUSv6 : http://www.opengroup.org/onlinepubs/000095399
  - SUSv7 : http://www.opengroup.org/onlinepubs/9699919799

----

{{tag>Stale}}