Signal Types
Signal
Value
Action
Comment
SIGHUP
1
Terminate
Hangup detected on controlling terminal or death of controlling process
SIGINT
2
Terminate
Interrupt from keyboard
SIGQUIT
3
Terminate
Quit from keyboard
SIGILL
4
Terminate
Illegal Instruction
SIGABRT
6
Dump Core
Abort signal from abort(3)
SIGFPE
8
Dump Core
Floating point exception
SIGKILL
9
Terminate
(Can't be caught)
(Can't be ignored)
Kill signal
SIGSEGV
11
Dump Core
Invalid memory reference
SIGPIPE
13
Terminate
Broken pipe: write to pipe with no readers
SIGALRM
14
Terminate
Timer signal from alarm(2)
SIGTERM
15
Terminate
Termination signal
SIGUSR1
30,10,16
Terminate
User-defined signal 1
SIGUSR2
31,12,17
Terminate
User-defined signal 2
SIGCHLD
20,17,18
Ignore
Child stopped or terminated
SIGCONT
19,18,25
 
Continue if stopped
SIGSTOP
17,19,23
Stop Process
(Can't be caught)
(Can't be ignored)
Stop process
SIGTSTP
18,20,24
Stop Process
Stop typed at tty
SIGTTIN
21,21,26
Stop Process
tty input for background process
SIGTTOU
22,22,27
Stop Process
tty output for background process
SIGIOT
6
Dump Core
(Non-POSIX.1)
IOT trap. A synonym for SIGABRT
SIGEMT
7,-,7
(Non-POSIX.1)
 
SIGBUS
10,7,10
Terminate
(Non-POSIX.1)
Bus error
SIGSYS
12,-,12
(Non-POSIX.1)
Bad argument to routine (SVID)
SIGSTKFLT
-,16,-
Terminate
(Non-POSIX.1)
Stack fault on coprocessor
SIGURG
16,23,21
Ignore
(Non-POSIX.1)
Urgent condition on socket (4.2 BSD)
SIGIO
23,29,22
Terminate
(Non-POSIX.1)
I/O now possible (4.2 BSD)
SIGPOLL
 
Terminate
(Non-POSIX.1)
Terminate synonym for SIGIO (System V)
SIGCLD
-,-,18
(Non-POSIX.1)
Terminate synonym for SIGCHLD
SIGXCPU
24,24,30
Terminate
(Non-POSIX.1)
CPU time limit exceeded (4.2 BSD)
SIGXFSZ
25,25,31
Terminate
(Non-POSIX.1)
File size limit exceeded (4.2 BSD)
SIGVTALRM
26,26,28
Terminate
(Non-POSIX.1)
Virtual alarm clock (4.2 BSD)
SIGPROF
27,27,29
Terminate
(Non-POSIX.1)
Profile alarm clock
SIGPWR
29,30,19
Terminate
(Non-POSIX.1)
Power failure (System V)
SIGINFO
29,-,-
(Non-POSIX.1)
Terminate synonym for SIGPWR
SIGLOST
-,-,-
Terminate
(Non-POSIX.1)
File lock lost
SIGWINCH
28,28,20
Ignore
(Non-POSIX.1)
Window resize signal (4.3 BSD, Sun)
SIGUNUSED
-,31,-
Terminate
(Non-POSIX.1)
Unused signal