bsd_signal(3C)						   Standard C Library Functions 					    bsd_signal(3C)

NAME

       bsd_signal - simplified signal facilities

SYNOPSIS

       #include <signal.h>

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

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 an 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 handler(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(3UCB) function for simple applications that are installing a single-argument sig-
       nal handler function.  If a BSD signal handler function is being installed that expects more than one argument, the application has  to	be
       modified  to use sigaction(2). The bsd_signal() function differs from signal(3UCB) 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(3UCB).

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Interface Stability	     |Standard			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       sigaction(2), sigaddset(3C), sigemptyset(3C), signal(3UCB), attributes(5), standards(5)

SunOS 5.10							    24 Jul 2002 						    bsd_signal(3C)