Predefined 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)
WCONTINUED (int)
WEXITED (int)
WSTOPPED (int)
WNOWAIT (int)
SIG_* constants
SIG_IGN (int)
SIG_DFL (int)
SIG_ERR (int)
SIGHUP (int)
SIGINFO (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)
SIGRTMIN (int)
SIGRTMAX (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)
SI_MESGQ (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.
Process Control error constants
Constants Description
PCNTL_E2BIG (int) Argument list too long
PCNTL_EACCES (int) Permission denied
PCNTL_EAGAIN (int) Resource temporarily unavailable
PCNTL_ECAPMODE (int) The process attempted an operation not permitted in capability mode while running in capability mode.
PCNTL_ECHILD (int) No child processes
PCNTL_EFAULT (int) Bad address
PCNTL_EINTR (int) Interrupted function call
PCNTL_EINVAL (int) Invalid argument
PCNTL_EIO (int) Input/output error
PCNTL_EISDIR (int) Is a directory
PCNTL_ELIBBAD (int) Accessing a corrupted shared library.
PCNTL_ELOOP (int) Too many levels of symbolic links
PCNTL_EMFILE (int) Too many open files. Commonly caused by exceeding the RLIMIT_NOFILE resource limit. Can also be caused by exceeding the limit specified in /proc/sys/fs/nr_open.
PCNTL_ENAMETOOLONG (int) Filename too long
PCNTL_ENFILE (int) Too many open files in system. On Linux, this is probably a result of encountering the /proc/sys/fs/file-max limit.
PCNTL_ENOENT (int) No such file or directory. Typically, this error results when a specified pathname does not exist, or one of the components in the directory prefix of a pathname does not exist, or the specified pathname is a dangling symbolic link.
PCNTL_ENOEXEC (int) Exec format error
PCNTL_ENOMEM (int) Not enough space/cannot allocate memory
PCNTL_ENOSPC (int) No space left on device
PCNTL_ENOTDIR (int) Not a directory
PCNTL_EPERM (int) Operation not permitted
PCNTL_ESRCH (int) No such process
PCNTL_ETXTBSY (int) Text file busy
PCNTL_EUSERS (int) Too many users
FORK_* constants
FORK_NOSIGCHLD (int)
FORK_WAITPID (int)
RF* constants
RFCFDG (int)
RFFDG (int)
RFLINUXTHPN (int)
RFNOWAIT (int)
RFPROC (int)
RFTHREAD (int)
RFTSIGZMB (int)
First argument to waitid (idtype)
P_ALL (int)
Select any children.
P_PID (int)
Select by process ID.
P_PGID (int)
Select by process group ID.
P_PIDFD (int)
Select by PID file descriptor. Specific to Linux (since Linux 5.4).
P_UID (int)
Select by effective user ID. Specific to NetBSD and FreeBSD.
P_GID (int)
Select by effective group ID. Specific to NetBSD and FreeBSD.
P_SID (int)
Select by session ID. Specific to NetBSD and FreeBSD.
P_JAILID (int)
Select by jail identifier. Specific to FreeBSD.
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User Contributed Notes 3 notes

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9
coder dot ua at gmail dot com
10 years ago
You should see all signals and their codes in your system using: kill -l
In my Debian GNU/Linux 7.6 (wheezy):

1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP
6) SIGABRT 7) SIGBUS 8) SIGFPE 9) SIGKILL 10) SIGUSR1
11) SIGSEGV 12) SIGUSR2 13) SIGPIPE 14) SIGALRM 15) SIGTERM
16) SIGSTKFLT 17) SIGCHLD 18) SIGCONT 19) SIGSTOP 20) SIGTSTP
21) SIGTTIN 22) SIGTTOU 23) SIGURG 24) SIGXCPU 25) SIGXFSZ
26) SIGVTALRM 27) SIGPROF 28) SIGWINCH 29) SIGIO 30) SIGPWR
31) SIGSYS 34) SIGRTMIN 35) SIGRTMIN+1 36) SIGRTMIN+2 37) SIGRTMIN+3
38) SIGRTMIN+4 39) SIGRTMIN+5 40) SIGRTMIN+6 41) SIGRTMIN+7 42) SIGRTMIN+8
43) SIGRTMIN+9 44) SIGRTMIN+10 45) SIGRTMIN+11 46) SIGRTMIN+12 47) SIGRTMIN+13
48) SIGRTMIN+14 49) SIGRTMIN+15 50) SIGRTMAX-14 51) SIGRTMAX-13 52) SIGRTMAX-12
53) SIGRTMAX-11 54) SIGRTMAX-10 55) SIGRTMAX-9 56) SIGRTMAX-8 57) SIGRTMAX-7
58) SIGRTMAX-6 59) SIGRTMAX-5 60) SIGRTMAX-4 61) SIGRTMAX-3 62) SIGRTMAX-2
63) SIGRTMAX-1 64) SIGRTMAX
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4
eclecticrob at gmail dot com
12 years ago
On OS X, the values of the constants are:

SIGHUP = 1
SIGINT = 2
SIGQUIT = 3
SIGILL = 4
SIGTRAP = 5
SIGABRT = 6
SIGIOT = 6
SIGBUS = 10
SIGFPE = 8
SIGUSR1 = 30
SIGSEGV = 11
SIGUSR2 = 31
SIGPIPE = 13
SIGALRM = 14
SIGTERM = 15
SIGSTKFLT not defined
SIGCLD not defined
SIGCHLD = 20
SIGCONT = 19
SIGTSTP = 18
SIGTTIN = 21
SIGTTOU = 22
SIGURG = 16
SIGXCPU = 24
SIGXFSZ = 25
SIGVTALRM = 26
SIGPROF = 27
SIGWINCH = 28
SIGPOLL not defined
SIGIO = 23
SIGPWR not defined
SIGSYS = 12
SIGBABY = 12
SIG_BLOCK = 1
SIG_UNBLOCK = 2
SIG_SETMASK = 3
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-1
eclecticrob at gmail dot com
12 years ago
On RedHat, the values of the constants are:

Signal SIGHUP = 1
Signal SIGINT = 2
Signal SIGQUIT = 3
Signal SIGILL = 4
Signal SIGTRAP = 5
Signal SIGABRT = 6
Signal SIGIOT = 6
Signal SIGBUS = 7
Signal SIGFPE = 8
Signal SIGUSR1 = 10
Signal SIGSEGV = 11
Signal SIGUSR2 = 12
Signal SIGPIPE = 13
Signal SIGALRM = 14
Signal SIGTERM = 15
Signal SIGSTKFLT = 16
Signal SIGCLD = 17
Signal SIGCHLD = 17
Signal SIGCONT = 18
Signal SIGTSTP = 20
Signal SIGTTIN = 21
Signal SIGTTOU = 22
Signal SIGURG = 23
Signal SIGXCPU = 24
Signal SIGXFSZ = 25
Signal SIGVTALRM = 26
Signal SIGPROF = 27
Signal SIGWINCH = 28
Signal SIGPOLL = 29
Signal SIGIO = 29
Signal SIGPWR = 30
Signal SIGSYS = 31
Signal SIGBABY = 31
Signal SIG_BLOCK = 0
Signal SIG_UNBLOCK = 1
Signal SIG_SETMASK = 2
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