linux/posix · macos/posix · Standard Library

POSIX declarations used by Linux and macOS timing, descriptor, process, pipe, and context-switching helpers.

Functions that report failure with -1 set errno.

Constants

Error numbers

Name	Linux	macOS	Meaning
`EAGAIN`	`11`	`35`	Resource temporarily unavailable.
`EBADF`	—	`9`	Bad file descriptor.
`EINPROGRESS`	`115`	`36`	Operation in progress.
`EINTR`	`4`	`4`	Interrupted operation.
`ENOENT`	—	`2`	No such file or directory.
`EWOULDBLOCK`	`EAGAIN`	`EAGAIN`	Operation would block.

Descriptor control

Name	Linux	macOS	Meaning
`F_SETFD`	`2`	`2`	Sets descriptor flags.
`FD_CLOEXEC`	`1`	`1`	Close-on-exec descriptor flag.
`O_NONBLOCK`	`2048`	`4`	Nonblocking file-status flag.

Memory mappings

Name	Linux	macOS	Meaning
`MAP_ANONYMOUS`	`0x0020`	`0x1000`	Anonymous mapping flag.
`MAP_PRIVATE`	`0x0002`	`0x0002`	Private mapping flag.
`MAP_STACK`	`0x020000`	—	Stack mapping flag.

Open flags

Name	Linux	macOS	Meaning
`O_CLOEXEC`	`0x80000`	—	Close-on-exec open flag.
`O_CREAT`	`0x40`	—	Create-if-absent open flag.
`O_RDWR`	`0x2`	—	Read-and-write open flag.

Memory protections

Name	Linux	macOS	Meaning
`PROT_NONE`	`0x0`	`0x0`	No-access protection.
`PROT_READ`	`0x1`	`0x1`	Read protection.
`PROT_WRITE`	`0x2`	`0x2`	Write protection.

Process and wait

Name	Linux	macOS	Meaning
`SIGKILL`	`9`	`9`	Terminate-process signal.
`WNOHANG`	`1`	—	Do not wait for a child state change.

Clocks

Name	Linux	macOS	Meaning
`CLOCK_BOOTTIME`	`7`	—	Boot-time clock identifier.
`CLOCK_MONOTONIC`	`1`	`6`	Monotonic clock identifier.

Schemas

`clockid_t`

(-- clockid_t) Defines clock identifier storage.

Int32 alias

`__darwin_mcontext_data`

(-- __darwin_mcontext_data) Defines Darwin machine-context storage.

Nat8 824 array; macOS only

`itimerspec`

(-- itimerspec) Defines interval-timer settings.

Dict schema; Linux only

Linux

Field	Schema	Role
`it_interval`	`timespec`	timer interval
`it_value`	`timespec`	current timer expiration

`long`

(-- long) Defines signed integer storage.

Intx alias

`sigset_t`

(-- sigset_t) Defines signal-set storage.

Nat32 alias; macOS only

`stack_t`

(-- stack_t) Defines the stack used by a context.

Dict schema; macOS only

macOS

Field	Schema	Role
`ss_sp`	`Natx`	stack storage address
`ss_size`	`Natx`	stack size in bytes
`ss_flags`	`Int32`	stack flags

`time_t`

(-- time_t) Defines time-value storage.

Intx alias

`timespec`

(-- timespec) Defines seconds and nanoseconds for one time value.

Dict schema

Field	Schema	Role
`tv_sec`	`time_t`	seconds component
`tv_nsec`	`long`	nanoseconds component

`ucontext_t`

(-- ucontext_t) Defines user-context storage.

Linux: Ucontext alias; macOS: Dict schema

Linux

Field	Schema	Role
`uc_flags`	`Natx`	context flags
`uc_link`	`[ucontext_t]` `Mref`	successor context
`uc_stack`	`{ss_sp:` `Natx; ss_flags:` `Int32; ss_size:` `Natx;}`	stack used by this context

The remaining fields are processor-specific: linux/architecture selects the processor layout for Ucontext, and dependent schemas such as stack_t belong to linux/architecture/Ucontext, not linux/posix. For the linux/architecture link, see epoll_event.

macOS

Field	Schema	Role
`uc_onstack`	`Int32`	alternate-stack state
`uc_sigmask`	`sigset_t`	signal mask
`uc_stack`	`stack_t`	stack used by this context
`uc_link`	`[ucontext_t]` `Mref`	successor context
`uc_mcsize`	`Natx`	machine-context size
`uc_mcontext`	`[__darwin_mcontext_data]` `Mref`	machine context
`__mcontext_data`	`__darwin_mcontext_data`	machine-context storage

Helpers

`WEXITSTATUS`

(status -- result) Extracts the exit status from a wait status for which WIFEXITED is true and returns an Int32.

`WIFEXITED`

(status -- result) Reports whether a wait status represents normal process termination as a Cond.

Imported functions

Stack effects list a C function's parameters with the first parameter on top; see importFunction.

`clock_gettime`

(tp clk_id -- result) Writes the selected clock time to one timespec.

Inputs

tp: timespec Ref caller-owned writable time storage; the call writes it.
clk_id: clockid_t clock identifier.

Outputs

result: Int32 0 on success, or -1 on failure.

`close`

(fildes -- result) Closes a file descriptor.

Inputs

fildes: Int32 file descriptor to close.

Outputs

result: Int32 0 on success, or -1 on failure.

`execvp`

(argv file -- result) Replaces the current process image with the named executable.

Inputs

argv: Natx address of a zero-terminated array of addresses of zero-terminated argument strings.
file: Natx address of a zero-terminated executable path; a name without a slash is searched for in the directories listed in PATH.

Outputs

result: Int32 -1 on failure; on success, the call does not return.

`fcntl`

(varargs cmd fildes -- result) Applies a descriptor command.

Inputs

varargs: List or Tuple holding the additional arguments, the first one as item 0; use () when there are none.
cmd: Int32 descriptor command.
fildes: Int32 file descriptor to control.

Outputs

result: Int32 command-specific result, or -1 on failure.

`fork`

(-- result) Creates a child process.

Inputs

None.

Outputs

result: Int32 child process identifier in the parent, 0 in the child, or -1 on failure.

`getcontext`

(ucp -- result) Saves the current user context.

Inputs

ucp: ucontext_t Ref caller-owned writable context storage; the call writes it.

Outputs

result: Int32 0 on success, or -1 on failure.

`getpid`

(-- result) Returns the calling process identifier.

Inputs

None.

Outputs

result: Int32 calling process identifier.

`kill`

(sig pid -- result) Sends a signal to a process.

Inputs

sig: Int32 signal number.
pid: Int32 process identifier.

Outputs

result: Int32 0 on success, or -1 on failure.

`makecontext`

(varargs argc func ucp --) Initializes a user context for a function call.

Inputs

varargs: List or Tuple holding the additional arguments, the first one as item 0; use () when there are none.
argc: Int32 number of additional arguments passed to the target function.
func: Natx address of the target function.
ucp: ucontext_t Ref context obtained with getcontext, with uc_stack and uc_link configured; the call sets its entry point and arguments.

Outputs

None.

`mmap`

(offset fd flags prot length addr -- result) Maps memory into the process address space.

Inputs

offset: Intx mapping offset in bytes, a multiple of the page size.
fd: Int32 file descriptor for the mapped object, or -1 with MAP_ANONYMOUS in flags for an anonymous mapping.
flags: Int32 mapping flags, which must include MAP_PRIVATE or MAP_SHARED.
prot: Int32 memory-protection flags.
length: Natx nonzero mapping length in bytes.
addr: Natx requested mapping address, or 0nx for no address hint.

Outputs

result: Natx mapped address, or the all-bits-one value on failure.

`mprotect`

(prot length addr -- result) Changes protection on a memory range.

Inputs

prot: Int32 memory-protection flags.
length: Natx range length in bytes.
addr: Natx start address of the memory range, a multiple of the page size.

Outputs

result: Int32 0 on success, or -1 on failure.

`open`

(varargs flags path -- result) Opens a path with flags.

Inputs

varargs: List or Tuple holding the additional arguments, the first one as item 0; use () when there are none.
flags: Int32 open flags; O_CREAT also requires the file-creation mode as an Int32 item of varargs.
path: Natx address of a zero-terminated path string.

Outputs

result: Int32 new descriptor, or -1 on failure.

Remarks

Linux declaration only.

`pause`

(-- result) Waits for a signal.

Inputs

None.

Outputs

result: Int32 -1 after a signal handler returns.

Remarks

Linux declaration only.

`pipe`

(filedes -- result) Creates a pipe and fills its descriptor pair.

Inputs

filedes: {in: Int32; out: Int32;} Ref caller-owned descriptor-pair storage; the call writes the read descriptor to in and the write descriptor to out.

Outputs

result: Int32 0 on success, or -1 on failure.

`read`

(size buffer filedes -- result) Reads bytes from a file descriptor.

Inputs

size: Natx number of bytes requested.
buffer: Natx address of writable byte storage.
filedes: Int32 file descriptor to read.

Outputs

result: Intx number of bytes read, 0ix at end of file, or -1ix on failure.

`swapcontext`

(ucp oucp -- result) Saves one user context and activates another.

Inputs

ucp: ucontext_t Ref context to activate.
oucp: ucontext_t Ref caller-owned writable storage for the saved context; the call writes it.

Outputs

result: Int32 0 when the saved context is resumed, or -1 on failure.

`waitpid`

(options wstatus pid -- result) Waits for a child process state change.

Inputs

options: Int32 wait options.
wstatus: Int32 Ref caller-owned writable storage that receives the wait status, or a typed NIL Int32 Ref when the status is not needed.
pid: Int32 child process identifier to wait for.

Outputs

result: Int32 child process identifier, 0 when WNOHANG finds no state change, or -1 on failure.

`write`

(size buffer filedes -- result) Writes bytes to a file descriptor.

Inputs

size: Natx number of bytes to write.
buffer: Natx address of bytes to write.
filedes: Int32 file descriptor to write.

Outputs

result: Intx number of bytes written, or -1ix on failure.

Examples

Signature examples

Printing imported names during compilation shows exact imported signatures for representative declarations.

"control"     use
"linux/posix" use

{} Int32 {} [
  @clock_gettime printStack _:;
  @fcntl printStack _:;
  @pipe printStack _:;
  @waitpid printStack _:;
  0
] "main" exportFunction

Expected Output During Compilation

{clk_id: Int32; tp: {tv_sec: Intx; tv_nsec: Intx;} Ref;} Int32 {convention: "";} codeRef
{fildes: Int32; cmd: Int32;} Int32 {convention: ""; variadic: TRUE;} codeRef
{filedes: {in: Int32; out: Int32;} Ref;} Int32 {convention: "";} codeRef
{pid: Int32; wstatus: Int32 Ref; options: Int32;} Int32 {convention: "";} codeRef

macOS signature and layout example

Printing representative macOS declarations during compilation shows exact imported signatures and the field count of ucontext_t.

"control"     use
"macos/posix" use

{} Int32 {} [
  @clock_gettime printStack _:;
  @getpid printStack _:;
  ucontext_t fieldCount printStack _:;
  0
] "main" exportFunction

Expected Output During Compilation

{clk_id: Int32; tp: {tv_sec: Intx; tv_nsec: Intx;} Ref;} Int32 {convention: "";} codeRef
{} Int32 {convention: "";} codeRef
7

Pipe round-trip

"String"  use
"control" use
"posix"   use

{} Int32 {} [
  fds: {in: Int32; out: Int32;};
  pipeResult: @fds pipe;
  bytesWritten: 1nx "A" storageAddress fds.out new write;
  byte: 0n8;
  bytesRead: 1nx @byte storageAddress fds.in new read;
  closeIn: fds.in new close;
  closeOut: fds.out new close;
  ("pipe=" pipeResult LF
    "written=" bytesWritten LF
    "read=" bytesRead LF
    "byte=" byte LF
    "closeIn=" closeIn LF
    "closeOut=" closeOut LF) printList
  0
] "main" exportFunction

Expected Output

pipe=0
written=1
read=1
byte=65
closeIn=0
closeOut=0

Constants

Error numbers

Descriptor control

Memory mappings

Open flags

Memory protections

Process and wait

Clocks

Schemas

Linux

macOS

Linux

macOS

Helpers

Imported functions

Inputs

Outputs

Inputs

Outputs

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Outputs

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Outputs

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Outputs

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Inputs

Outputs

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Remarks

Inputs

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Remarks

Inputs

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Examples

Signature examples

Expected Output During Compilation

macOS signature and layout example

Expected Output During Compilation

Pipe round-trip

Expected Output

See also