| NAME Default Action Description
SIGHUP terminate process terminal line hangup
SIGINT terminate process interrupt program
SIGQUIT create core image quit program
SIGILL create core image illegal instruction
SIGTRAP create core image trace trap
SIGABRT create core image abort(3)
|call (formerly SIGIOT)|
| SIGEMT create core image emulate instruction executed
SIGFPE create core image floating-point exception
SIGKILL terminate process kill program
SIGBUS create core image bus error
SIGSEGV create core image segmentation violation
SIGSYS create core image non-existent system call invoked
SIGPIPE terminate process write on a pipe with no reader
SIGALRM terminate process real-time timer expired
SIGTERM terminate process software termination signal
SIGURG discard signal urgent condition present on socket
SIGSTOP stop process stop (cannot be caught or ignored)
SIGTSTP stop process stop signal generated from keyboard
SIGCONT discard signal continue after stop
SIGCHLD discard signal child status has changed
SIGTTIN stop process background read attempted from control terminal
SIGTTOU stop process background write attempted to control terminal
SIGIO discard signal I/O
|is possible on a descriptor (see fcntl(2))|
|SIGXCPU terminate process cpu time limit exceeded (see||setrlimit(2))|
|SIGXFSZ terminate process file size limit exceeded (see||setrlimit(2))|
|SIGVTALRM terminate process virtual time alarm (see||setitimer(2))|
|SIGPROF terminate process profiling timer alarm (see||setitimer(2))|
| SIGWINCH discard signal Window size change
SIGINFO discard signal status request from keyboard
SIGUSR1 terminate process User defined signal 1
SIGUSR2 terminate process User defined signal 2
Once a signal handler is installed, it remains installed until another sigvec call is made, or an execve(2) is performed. A signal-specific default action may be reset by setting sv_handler to SIG_DFL. The defaults are process termination, possibly with core dump; no action; stopping the process; or continuing the process. See the above signal list for each signals default action. If sv_handler is SIG_IGN current and pending instances of the signal are ignored and discarded.
If a signal is caught during the system calls listed below, the call is normally restarted. The call can be forced to terminate prematurely with an EINTR error return by setting the SV_INTERRUPT bit in sv_flags. The affected system calls include read(2), write(2), sendto(2), recvfrom(2), sendmsg(2) and recvmsg(2) on a communications channel or a slow device (such as a terminal, but not a regular file) and during a wait(2) or ioctl(2). However, calls that have already committed are not restarted, but instead return a partial success (for example, a short read count).
The execve(2) system call reinstates the default action for all signals which were caught and resets all signals to be caught on the user stack. Ignored signals remain ignored; the signal mask remains the same; signals that interrupt system calls continue to do so.
The mask specified in vec is not allowed to block SIGKILL or SIGSTOP. This is done silently by the system.
The SV_INTERRUPT flag is not available in BSD 4.2 , hence it should not be used if backward compatibility is needed.
.Rv -std sigvec
On the VAX-11 The handler routine can be declared:void handler(sig, code, scp) int sig, code; struct sigcontext *scp;
Here sig is the signal number, into which the hardware faults and traps are mapped as defined below. The code argument is either a constant as given below or, for compatibility mode faults, the code provided by the hardware (Compatibility mode faults are distinguished from the other SIGILL traps by having PSL_CM set in the psl). The scp argument is a pointer to the sigcontext structure (defined in
.In signal.h ) , used to restore the context from before the signal.
The sigvec function will fail and no new signal handler will be installed if one of the following occurs:
[EFAULT] Either vec or ovec points to memory that is not a valid part of the process address space. [EINVAL] The sig argument is not a valid signal number. [EINVAL] An attempt is made to ignore or supply a handler for SIGKILL or SIGSTOP.
kill(1), kill(2), ptrace(2), sigaction(2), sigaltstack(2), sigblock(2), sigpause(2), sigprocmask(2), sigsetmask(2), sigsuspend(2), setjmp(3), siginterrupt(3), signal(3), sigsetops(3), tty(4)
This manual page is still confusing.