SIGNAL

NAME

signal - list of available signals

DESCRIPTION

Linux supports the signals listed below. Several signal numbers are architecture dependent. First the signals described in POSIX.1.

SignalValueActionComment




or death of controlling process
SIGINT 2AInterrupt from keyboard
SIGQUIT 3AQuit from keyboard
SIGILL 4AIllegal Instruction
SIGABRT 6CAbort signal from abort(3)
SIGFPE 8CFloating point exception
SIGKILL 9AEFKill signal
SIGSEGV11CInvalid memory reference
SIGPIPE13ABroken pipe: write to pipe with no readers
SIGALRM14ATimer signal from alarm(2)
SIGTERM15ATermination signal
SIGUSR130,10,16AUser-defined signal 1
SIGUSR231,12,17AUser-defined signal 2
SIGCHLD20,17,18BChild stopped or terminated
SIGCONT19,18,25Continue if stopped
SIGSTOP17,19,23DEFStop process
SIGTSTP18,20,24DStop typed at tty
SIGTTIN21,21,26Dtty input for background process
SIGTTOU22,22,27Dtty output for background process

Next various other signals.

SignalValueActionComment




SIGIOT6CGIOT trap. A synonym for SIGABRT
SIGEMT7,-,7G
SIGBUS10,7,10AGBus error
SIGSYS12,-,12GBad argument to routine (SVID)
SIGSTKFLT-,16,-AGStack fault on coprocessor
SIGURG16,23,21BGUrgent condition on socket (4.2 BSD)
SIGIO23,29,22AGI/O now possible (4.2 BSD)
SIGPOLLAGA synonym for SIGIO (System V)
SIGCLD-,-,18GA synonym for SIGCHLD
SIGXCPU24,24,30AGCPU time limit exceeded (4.2 BSD)
SIGXFSZ25,25,31AGFile size limit exceeded (4.2 BSD)
SIGVTALRM26,26,28AGVirtual alarm clock (4.2 BSD)
SIGPROF27,27,29AGProfile alarm clock
SIGPWR29,30,19AGPower failure (System V)
SIGINFO29,-,-GA synonym for SIGPWR
SIGLOST-,-,-AGFile lock lost
SIGWINCH28,28,20BGWindow resize signal (4.3 BSD, Sun)
SIGUNUSED-,31,-AGUnused signal
(Here - denotes that a signal is absent; there where three values are given, the first one is usually valid for alpha and sparc, the middle one for i386 and ppc, the last one for mips. Signal 29 is SIGINFO / SIGPWR on an alpha but SIGLOST on a sparc.)

The letters in the "Action" column have the following meanings:

A
Default action is to terminate the process.
B
Default action is to ignore the signal.
C
Default action is to dump core.
D
Default action is to stop the process.
E
Signal cannot be caught.
F
Signal cannot be ignored.
G
Not a POSIX.1 conformant signal.
 

CONFORMING TO

POSIX.1  

BUGS

SIGIO and SIGLOST have the same value. The latter is commented out in the kernel source, but the build process of some software still thinks that signal 29 is SIGLOST.  

SEE ALSO

kill(1), kill(2), setitimer(2)