Method: Signal#trap
- Defined in:
- signal.c
#trap(signal, command) ⇒ Object (private) #trap(signal) {|| ... } ⇒ Object (private)
Specifies the handling of signals. The first parameter is a signal name (a string such as “SIGALRM”, “SIGUSR1”, and so on) or a signal number. The characters “SIG” may be omitted from the signal name. The command or block specifies code to be run when the signal is raised. If the command is the string “IGNORE” or “SIG_IGN”, the signal will be ignored. If the command is “DEFAULT” or “SIG_DFL”, the Ruby’s default handler will be invoked. If the command is “EXIT”, the script will be terminated by the signal. If the command is “SYSTEM_DEFAULT”, the operating system’s default handler will be invoked. Otherwise, the given command or block will be run. The special signal name “EXIT” or signal number zero will be invoked just prior to program termination. trap returns the previous handler for the given signal.
Signal.trap(0, proc { puts "Terminating: #{$$}" })
Signal.trap("CLD") { puts "Child died" }
fork && Process.wait
produces:
Terminating: 27461
Child died
Terminating: 27460
1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 |
# File 'signal.c', line 1387
static VALUE
sig_trap(int argc, VALUE *argv, VALUE _)
{
int sig;
sighandler_t func;
VALUE cmd;
rb_check_arity(argc, 1, 2);
sig = trap_signm(argv[0]);
if (reserved_signal_p(sig)) {
const char *name = signo2signm(sig);
if (name)
rb_raise(rb_eArgError, "can't trap reserved signal: SIG%s", name);
else
rb_raise(rb_eArgError, "can't trap reserved signal: %d", sig);
}
if (argc == 1) {
cmd = rb_block_proc();
func = sighandler;
}
else {
cmd = argv[1];
func = trap_handler(&cmd, sig);
}
if (rb_obj_is_proc(cmd) &&
!rb_ractor_main_p() && !rb_ractor_shareable_p(cmd)) {
cmd = rb_proc_isolate(cmd);
}
return trap(sig, func, cmd);
}
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