SIGNAL(7) Linux Programmer's Manual SIGNAL(7)
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.
Signal Value Action Comment
-------------------------------------------------------------------------
SIGHUP 1 A Hangup detected on controlling terminal
or death of controlling process
SIGINT 2 A Interrupt from keyboard
SIGQUIT 3 A Quit from keyboard
SIGILL 4 A Illegal Instruction
SIGABRT 6 C Abort signal from abort(3)
SIGFPE 8 C Floating point exception
SIGKILL 9 AEF Kill signal
SIGSEGV 11 C Invalid memory reference
SIGPIPE 13 A Broken pipe: write to pipe with no readers
SIGALRM 14 A Timer signal from alarm(2)
SIGTERM 15 A Termination signal
SIGUSR1 30,10,16 A User-defined signal 1
SIGUSR2 31,12,17 A User-defined signal 2
SIGCHLD 20,17,18 B Child stopped or terminated
SIGCONT 19,18,25 Continue if stopped
SIGSTOP 17,19,23 DEF Stop process
SIGTSTP 18,20,24 D Stop typed at tty
SIGTTIN 21,21,26 D tty input for background process
SIGTTOU 22,22,27 D tty output for background process
Next various other signals.
Signal Value Action Comment
---------------------------------------------------------------------
SIGTRAP 5 CG Trace/breakpoint trap
SIGIOT 6 CG IOT trap. A synonym for SIGABRT
SIGEMT 7,-,7 G
SIGBUS 10,7,10 AG Bus error
SIGSYS 12,-,12 G Bad argument to routine (SVID)
SIGSTKFLT -,16,- AG Stack fault on coprocessor
SIGURG 16,23,21 BG Urgent condition on socket (4.2 BSD)
SIGIO 23,29,22 AG I/O now possible (4.2 BSD)
SIGPOLL AG A synonym for SIGIO (System V)
SIGCLD -,-,18 G A synonym for SIGCHLD
SIGXCPU 24,24,30 AG CPU time limit exceeded (4.2 BSD)
SIGXFSZ 25,25,31 AG File size limit exceeded (4.2 BSD)
SIGVTALRM 26,26,28 AG Virtual alarm clock (4.2 BSD)
SIGPROF 27,27,29 AG Profile alarm clock
SIGPWR 29,30,19 AG Power failure (System V)
SIGINFO 29,-,- G A synonym for SIGPWR
SIGLOST -,-,- AG File lock lost
SIGWINCH 28,28,20 BG Window resize signal (4.3 BSD, Sun)
SIGUNUSED -,31,- AG Unused 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 com*
mented 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)
