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(1) 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 Linux 1.3.88 April 14, 1996 1 SIGNAL(7) Linux Programmer's Manual SIGNAL(7) 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). Linux 1.3.88 April 14, 1996 2