Date: 2018.9.30



Signal     Value     Action   Comment
SIGHUP 1 Term Hangup detected on controlling terminal
or death of controlling process
SIGINT 2 Term Interrupt from keyboard
SIGQUIT 3 Core Quit from keyboard
SIGILL 4 Core Illegal Instruction
SIGABRT 6 Core Abort signal from abort(3)
SIGFPE 8 Core Floating-point exception
SIGKILL 9 Term Kill signal
SIGSEGV 11 Core Invalid memory reference
SIGPIPE 13 Term Broken pipe: write to pipe with no
readers; see pipe(7)
SIGALRM 14 Term Timer signal from alarm(2)
SIGTERM 15 Term Termination signal
SIGUSR1 30,10,16 Term User-defined signal 1
SIGUSR2 31,12,17 Term User-defined signal 2
SIGCHLD 20,17,18 Ign Child stopped or terminated
SIGCONT 19,18,25 Cont Continue if stopped
SIGSTOP 17,19,23 Stop Stop process
SIGTSTP 18,20,24 Stop Stop typed at terminal
SIGTTIN 21,21,26 Stop Terminal input for background process
SIGTTOU 22,22,27 Stop Terminal output for background process

The signals SIGKILL and SIGSTOP cannot be caught, blocked, or

Next the signals not in the POSIX.1-1990 standard but described in
SUSv2 and POSIX.1-2001.

Signal Value Action Comment
SIGBUS 10,7,10 Core Bus error (bad memory access)
SIGPOLL Term Pollable event (Sys V).
Synonym for SIGIO
SIGPROF 27,27,29 Term Profiling timer expired
SIGSYS 12,31,12 Core Bad system call (SVr4);
see also seccomp(2)
SIGTRAP 5 Core Trace/breakpoint trap
SIGURG 16,23,21 Ign Urgent condition on socket (4.2BSD)
SIGVTALRM 26,26,28 Term Virtual alarm clock (4.2BSD)
SIGXCPU 24,24,30 Core CPU time limit exceeded (4.2BSD);
see setrlimit(2)
SIGXFSZ 25,25,31 Core File size limit exceeded (4.2BSD);
see setrlimit(2)