raise_default_signal(3) [netbsd man page]

RAISE_DEFAULT_SIGNAL(3) 				   BSD Library Functions Manual 				   RAISE_DEFAULT_SIGNAL(3)

NAME

     raise_default_signal -- raise the default signal handler

LIBRARY

     System Utilities Library (libutil, -lutil)

SYNOPSIS

     #include <util.h>

     int
     raise_default_signal(int sig);

DESCRIPTION

     The raise_default_signal() function raises the default signal handler for the signal sig.	This function may be used by a user-defined signal
     handler router to ensure that a parent process receives the correct notification of a process termination by a signal.  This can be used to
     avoid a common programming mistake when terminating a process from a custom SIGINT or SIGQUIT signal handler.

     The operations performed are:

	   1.	Block all signals, using sigprocmask(2).

	   2.	Set the signal handler for signal sig to the default signal handler (SIG_DFL).

	   3.	raise(3) signal sig.

	   4.	Unblock signal sig to deliver it.

	   5.	Restore the original signal mask and handler, even if there was a failure.

     See signal(7) for a table of signals and default actions.

     The raise_default_signal() function should be async-signal-safe.

RETURN VALUES

     Upon successful completion, a value of 0 is returned.  Otherwise, a value of -1 is returned and the global variable errno is set to indicate
     the error.

ERRORS

     The raise_default_signal() function may fail and set errno for any of the errors specified for the functions sigemptyset(3), sigfillset(3),
     sigaddset(3), sigprocmask(2), sigaction(2), or raise(3).

SEE ALSO

     sigaction(2), sigprocmask(2), raise(3), signal(7)

HISTORY

     The raise_default_signal() function first appeared in NetBSD 5.0.

BSD
								September 25, 2007							       BSD

BSD_SIGNAL(3)						   BSD Library Functions Manual 					     BSD_SIGNAL(3)

NAME

     bsd_signal -- simplified signal facilities

SYNOPSIS

     #include <signal.h>

     void (*
     bsd_signal(int sig, void (*func)(int)))(int);

     or in an equivalent but easier to read typedef'd version:

     typedef void (*sig_t) (int);

     sig_t
     bsd_signal(int sig, sig_t func);

DESCRIPTION

     The bsd_signal() function provides a partially compatible interface for programs written to historical system interfaces (see USAGE below).

     The function call bsd_signal(sig, func) has the effect as if implemented as:

	   void (*bsd_signal(int sig, void (*func)(int)))(int)
	   {
	       struct sigaction act, oact;

	       act.sa_handler = func;
	       act.sa_flags = SA_RESTART;
	       sigemptyset(&act.sa_mask);
	       sigaddset(&act.sa_mask, sig);
	       if (sigaction(sig, &act, &oact) == -1)
		   return(SIG_ERR);
	       return(oact.sa_handler);
	   }

     The handler function should be declared:

	   void func(int sig)

     where sig is the signal number.  The behavior is undefined if func() is a function that takes more than one argument, or an argument of a
     different type.

RETURN VALUES

     Upon successful completion, bsd_signal() returns the previous action for sig.  Otherwise, SIG_ERR is returned and errno is set to indicate
     the error.

ERRORS

     Refer to sigaction(2).

USAGE

     This function is a direct replacement for the BSD signal(3) function for simple applications that are installing a single-argument signal
     handler function.	If a BSD signal handler function is being installed that expects more than one argument, the application has to be modi-
     fied to use sigaction(2).	The bsd_signal() function differs from signal(3) in that the SA_RESTART flag is set and the SA_RESETHAND will be
     clear when bsd_signal() is used.  The state of these flags is not specified for signal(3).

SEE ALSO

     sigaction(2), sigaddset(3), sigemptyset(3), signal(3)

STANDARDS

     The bsd_signal() function conforms to IEEE Std 1003.1-2001 (``POSIX.1'').

BSD
								 December 20, 2003							       BSD