Can I Use a System Call?

Can I Use a System Call?

Cosmopolitan Libc wraps system calls to provide high-level access to binary kernel interfaces. Linux is the gold standard for our suppport. However, if your program works on Linux, then it might not work on other platforms depending on which functions you use. The following table should help illuminate the portability of functions.

Function	Linux	FreeBSD	OpenBSD	NetBSD	MacOS	Windows	Metal
read	best	best	best	best	best	ok	good
write	best	best	best	best	best	ok	good
pread	best	best	best	best	best	ok	zipos
pwrite	best	best	best	best	best	ok	zipos
readv	best	best	best	best	best	ok	best
writev	best	best	best	best	best	ok	best
preadv	2009+	v2.1+	v2.1+	v2.1+	v2.1+	v2.1+	v2.1+
pwritev	2009+	v2.1+	v2.1+	v2.1+	v2.1+	v2.1+	v2.1+
close	best	best	best	best	best	slow	best
fstatat	best	best	best	best	best	smudged	best
fstat	best	best	best	best	best	spotty	best
statfs	best	best	best	best	best	best	fault
fstatfs	best	best	best	best	best	best	fault
_Exit	best	best	best	best	best	best	reset
_Exit1	best	best	rc=0	rc=0	rc=0	best	reset
fork	best	best	slow	best	best	slow	fault
vfork	best	best	fork	best	fork	fork	fault
clone	best	thread	thread	thread	thread	thread	enosys
futexes	best	sched_yield	good	sched_yield	select	millis	n/a
tls	%fs	%fs	%fs	%fs	%gs	%gs	%fs
arch_prctl	best	best	restricted	best	restricted	forbidden	best
fsgsbase	finally	works	forbidden	forbidden	forbidden	broken	best
fopenat O_RDONLY	best	best	best	best	best	best	zipos
fopenat O_RDWR	best	best	best	best	best	best	todo
fopenat O_TMPFILE	best	einval	einval	einval	einval	einval	einval
mmap MAP_PRIVATE	best	best	best	best	best	no cow	best
mmap MAP_SHARED	best	best	best	best	best	best	best
mmap MAP_STACK	fast+safe	fast+safe	safe	safe	safe	faked	safe
mmap MAP_POPULATE	best	best	ignored	ignored	ignored	ignored	ignored
mmap MAP_CONCEAL	ignored	best	best	best	ignored	ignored	ignored
poll	best	best	best	best	best	polling	best
select	best	best	best	best	best	polling	fault
pselect	best	best	best	best	best	polling	fault
ppoll	best	best	best	best	non-atomic	polling	best
lseek	best	best	best	best	best	best	best
pledge	2.6.23+	enosys	best	enosys	enosys	enosys	fault
unveil	5.13+	enosys	best	enosys	enosys	enosys	fault
msync	best	best	best	best	best	partial	todo
mprotect	best	best	best	best	best	best	todo
munmap	best	best	best	best	best	best	best
sigaction ucontext_t	best	best	best	best	best	best	enosys
sigprocmask	best	best	best	best	best	simulated	no-op
sigsuspend	best	best	best	best	best	simulated	no-op
sigpending	best	best	best	best	best	simulated	no-op
clock_gettime REALTIME	fastest	good	good	good	gettimeofday	fastest	enosys
clock_gettime MONOTONIC	fastest	good	good	good	rdtsc	rdtsc	enosys
clock_getres	kinda	good	good	ok	faked	rdtsc	enosys
ioctl TCGETS	best	best	best	best	best	ok	wip
ioctl TCSETS	best	best	best	best	best	ok	wip
ioctl TIOCGWINSZ	best	best	best	best	best	good	wip
ioctl FIOCLEX	best	best	best	best	best	best	wip
ioctl FIONBIO	best	best	best	best	best	best	fault
ioctl SIOCGIFCONF	best	best	best	best	best	best	fault
ioctl SIOCGIFADDR	best	best	best	best	best	best	fault
ioctl SIOCGIFNETMASK	best	best	best	best	best	best	fault
ioctl SIOCGIFBRDADDR	best	best	best	best	best	best	fault
ioctl SIOCGIFDSTADDR	best	best	best	best	best	best	fault
ioctl SIOCGIFFLAGS	best	best	best	best	best	best	fault
openpty	v2.0+	v2.1+	v2.1+	v2.1+	v2.1+	enosys	enosys
ptsname	v2.0+	v2.1+	hairy	v2.1+	v2.1+	enosys	enosys
flock	good	good	good	good	good	good	fault
sync	notest	notest	notest	notest	notest	flush	fault
fsync	notest	notest	notest	notest	notest	flush	fault
fdatasync	notest	notest	notest	notest	notest	flush	fault
sync_file_range	notest	fdatasync	fdatasync	fdatasync	fdatasync	fdatasync	fault
copy_file_range	5.9+	13+	enosys	enosys	enosys	enosys	fault
sendfile	best	best	enosys	enosys	best	best	enosys
splice	5.9+	enosys	enosys	enosys	enosys	enosys	fault
closefrom	5.9+	best	best	enosys	enosys	enosys	enosys
close_range	5.9+	13+	enosys	enosys	enosys	enosys	enosys
fadvise	best	best	enosys	best	enosys	most	enosys
posix_fadvise	best	best	enosys	best	enosys	most	enosys
truncate	best	best	best	best	best	best	fault
ftruncate	best	best	best	best	best	best	fault
faccessat	best	best	best	best	best	best	fault
pipe	best	best	best	best	best	best	fault
pipe2	2008+	best	best	best	non-atomic	best	fault
socketpair	best	best	best	best	best	best	fault
getcwd	best	best	best	best	best	best	fault
chdir	best	best	best	best	best	hairy	fault
fchdir	best	best	best	best	best	hairy	fault
renameat	best	best	best	best	best	best	fault
mkdirat	best	best	best	best	best	best	fault
linkat	best	best	best	best	best	admin-only	fault
unlinkat	best	best	best	best	best	hairy	fault
readlinkat	best	best	best	best	best	best	fault
sched_yield	best	best	best	best	select	best	no-op
memfd_create	best	enosys	enosys	enosys	enosys	enosys	fault
sys_mremap	best	enosys	enosys	good	enosys	enosys	enosys
mincore	best	best	best	best	best	enosys	fault
madvise	best	best	best	best	best	some	fault
dup	best	best	best	best	best	best	fault
dup2	best	best	best	best	best	best	fault
dup3	2008+	non-atomic	best	best	non-atomic	best	fault
fcntl F_DUPFD	best	best	best	best	best	best	fault
fcntl F_DUPFD_CLOEXEC	2008+	best	best	best	best	best	fault
fcntl Advisory Locks	good	good	good	good	good	best (v2.1)	fault
fcntl F_GETFL	best	best	best	best	best	best	fault
fcntl F_SETFL	best	best	best	best	best	einval	fault
fcntl F_GETFD	best	best	best	best	best	best	fault
fcntl F_SETFD	best	best	best	best	best	best	fault
nanosleep	best	best	best	best	micros	millis	enosys
setitimer	best	best	best	best	best	kludge	fault
gettid	best	good	good	good	good	good	fault
getpid	best	best	best	best	best	best	fault
getppid	best	best	best	best	best	slow	fault
getrandom	2014+	sysctl	getentropy	sysctl	getentropy	SysFun036	rdrand
umask	best	best	best	best	best	no-op	fault
issetugid	best	best	best	best	best	best	zero
setuid	best	best	best	best	best	no-op	fault
setgid	best	best	best	best	best	no-op	fault
setreuid	best	best	best	best	best	enosys	fault
setregid	best	best	best	best	best	enosys	fault
setresuid	best	best	best	faked	faked	enosys	fault
setresgid	best	best	best	faked	faked	enosys	fault
socket	best	best	best	best	best	best	fault
bind	best	best	best	best	best	good	fault
connect	best	best	best	best	best	good	fault
accept	best	best	best	best	best	good	fault
accept4	2009+	best	best	best	non-atomic	good	fault
sendto	best	best	best	best	best	good	fault
recvfrom	best	best	best	best	best	good	fault
sendmsg	good	ok	ok	ok	ok	ok	fault
recvmsg	good	ok	ok	ok	ok	ok	fault
shutdown	best	best	best	best	good	best	fault
getsockname	best	best	best	best	best	best	fault
getpeername	best	best	best	best	best	best	fault
getsockopt	best	narrow	narrow	narrow	narrow	narrow	fault
setsockopt SO_TYPE	best	best	best	best	best	best	fault
setsockopt SO_DEBUG	best	best	best	best	best	best	fault
setsockopt SO_ERROR	best	best	best	best	best	best	fault
setsockopt SO_BROADCAST	best	best	best	best	best	best	fault
setsockopt SO_REUSEADDR	best	best	best	best	best	n/a	fault
setsockopt SO_REUSEPORT	superior	best	best	best	best	best	fault
setsockopt SO_KEEPALIVE	best	best	best	best	best	best	fault
setsockopt SO_ACCEPTCONN	best	best	best	best	best	best	fault
setsockopt SO_DONTROUTE	best	best	best	best	best	best	fault
setsockopt SO_SNDBUF	best	best	best	best	best	best	fault
setsockopt SO_RCVBUF	best	best	best	best	best	best	fault
setsockopt SO_SNDLOWAT	best	best	best	best	best	best	fault
setsockopt SO_RCVLOWAT	best	best	best	best	best	best	fault
setsockopt TCP_NODELAY	best	best	best	best	best	best	fault
setsockopt TCP_CORK	best	best	best	best	best	best	fault
setsockopt TCP_FASTOPEN	best	best	enopro	enopro	enopro	best	enosys
setsockopt TCP_QUICKACK	best	enopro	enopro	enopro	enopro	enopro	fault
execve	best	best	best	best	best	kludge	fault
wait4	best	best	best	best	best	messy	fault
kill	best	best	best	best	best	limited	fault
tkill	best	ok	ok	ok	ok	ok	fault
tgkill	best	enosys	enosys	enosys	enosys	enosys	fault
uname	best	best	best	best	best	best	enosys
fchmodat	best	best	best	best	best	enosys	fault
fchownat	best	best	best	best	best	enosys	fault
chroot	works	works	works	works	works	enosys	fault
mount	notest	notest	notest	notest	notest	enosys	fault
reboot	notest	notest	notest	notest	notest	notest	fault
utimensat	2008+	1e-9	1e-9	1e-9	1e-6	1e-7	fault
sched_setaffinity	best	none	none	broken	none	best	fault
sched_getaffinity	best	none	none	broken	none	ugly	fault
sched_setscheduler	best	good	none	good	none	none	fault
sched_getscheduler	best	good	none	good	none	none	fault
sched_setparam	best	good	none	good	none	none	fault
sched_getparam	best	good	none	good	none	none	fault
sched_get_priority_max	best	best	none	best	none	none	fault
sched_get_priority_min	best	best	none	best	none	none	fault
sched_rr_get_interval	best	best	none	none	none	none	fault
epoll	best	enosys	enosys	enosys	enosys	wepoll	fault
clock	cgt	cgt	cgt	cgt	getrusage	gpt	fault
getrusage	some	best	best	best	best	some	fault
setrlimit	best	ok	ok	ok	ok	RLIMIT_AS	fault
opendir	best	best	best	best	best	best	fault
gethostname	best	best	best	best	best	best	fault
getlogin_r	getenv	sys	sys	sys	sys	sys	enoent
login_tty	best	best	best	best	best	enosys	enosys

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