&reftitle.constants;

The following list of signals are supported by the Process Control functions. Please see your systems signal(7) man page for details of the default behavior of these signals.

# Process Control constants

`WNOHANG` (`int`)

`WUNTRACED` (`int`)

## SIG_* constants

`SIG_IGN` (`int`)

`SIG_DFL` (`int`)

`SIG_ERR` (`int`)

`SIGHUP` (`int`)

`SIGINT` (`int`)

`SIGQUIT` (`int`)

`SIGILL` (`int`)

`SIGTRAP` (`int`)

`SIGABRT` (`int`)

`SIGIOT` (`int`)

`SIGBUS` (`int`)

`SIGFPE` (`int`)

`SIGKILL` (`int`)

`SIGUSR1` (`int`)

`SIGSEGV` (`int`)

`SIGUSR2` (`int`)

`SIGPIPE` (`int`)

`SIGALRM` (`int`)

`SIGTERM` (`int`)

`SIGSTKFLT` (`int`)

`SIGCLD` (`int`)

`SIGCHLD` (`int`)

`SIGCONT` (`int`)

`SIGSTOP` (`int`)

`SIGTSTP` (`int`)

`SIGTTIN` (`int`)

`SIGTTOU` (`int`)

`SIGURG` (`int`)

`SIGXCPU` (`int`)

`SIGXFSZ` (`int`)

`SIGVTALRM` (`int`)

`SIGPROF` (`int`)

`SIGWINCH` (`int`)

`SIGPOLL` (`int`)

`SIGIO` (`int`)

`SIGPWR` (`int`)

`SIGSYS` (`int`)

`SIGBABY` (`int`)

`SIG_BLOCK` (`int`)

`SIG_UNBLOCK` (`int`)

`SIG_SETMASK` (`int`)

## SI_* constants

`SI_USER` (`int`)

`SI_NOINFO` (`int`)

`SI_KERNEL` (`int`)

`SI_QUEUE` (`int`)

`SI_TIMER` (`int`)

`SI_MSGGQ` (`int`)

`SI_ASYNCIO` (`int`)

`SI_SIGIO` (`int`)

`SI_TKILL` (`int`)

## CLD_* constants

`CLD_EXITED` (`int`)

`CLD_KILLED` (`int`)

`CLD_DUMPED` (`int`)

`CLD_TRAPPED` (`int`)

`CLD_STOPPED` (`int`)

`CLD_CONTINUED` (`int`)

## TRAP_* constants

`TRAP_BRKPT` (`int`)

`TRAP_TRACE` (`int`)

## POLL_* constants

`POLL_IN` (`int`)

`POLL_OUT` (`int`)

`POLL_MSG` (`int`)

`POLL_ERR` (`int`)

`POLL_PRI` (`int`)

`POLL_HUP` (`int`)

## ILL_* constants

`ILL_ILLOPC` (`int`)

`ILL_ILLOPN` (`int`)

`ILL_ILLADR` (`int`)

`ILL_ILLTRP` (`int`)

`ILL_PRVOPC` (`int`)

`ILL_PRVREG` (`int`)

`ILL_COPROC` (`int`)

`ILL_BADSTK` (`int`)

## FPE_* constants

`FPE_INTDIV` (`int`)

`FPE_INTOVF` (`int`)

`FPE_FLTDIV` (`int`)

`FPE_FLTOVF` (`int`)

`FPE_FLTUND` (`int`)

`FPE_FLTRES` (`int`)

`FPE_FLTINV` (`int`)

`FPE_FLTSUB` (`int`)

## SEGV_* constants

`SEGV_MAPERR` (`int`)

`SEGV_ACCERR` (`int`)

## BUS_* constants

`BUS_ADRALN` (`int`)

`BUS_ADRERR` (`int`)

`BUS_OBJERR` (`int`)

## CLONE_* constants

`CLONE_NEWNS` (`int`)

- Available as of PHP 7.4.0

`CLONE_NEWIPC` (`int`)

- Available as of PHP 7.4.0

`CLONE_NEWUTS` (`int`)

- Available as of PHP 7.4.0

`CLONE_NEWNET` (`int`)

- Available as of PHP 7.4.0

`CLONE_NEWPID` (`int`)

- Available as of PHP 7.4.0

`CLONE_NEWUSER` (`int`)

- Available as of PHP 7.4.0

`CLONE_NEWCGROUP` (`int`)

- Available as of PHP 7.4.0

## PRIO_* constants

`PRIO_PGRP` (`int`)

`PRIO_USER` (`int`)

`PRIO_PROCESS` (`int`)

`PRIO_DARWIN_BG` (`int`)

- Available as of PHP 8.1.0.

`PRIO_DARWIN_THREAD` (`int`)

- Available as of PHP 8.1.0.