bsd_signal() -- replacement for BSD signal() function

SYNOPSIS

#include <signal.h>

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

The bsd_signal() function provides a partially compatible interface for programs written to historical system interfaces. This function is a direct replacement for the BSD signal() 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 modified to use sigaction(). The bsd_signal() function differs from signal() in that the SA_RESTART flag is set and the SA_RESETHAND flag is clear when bsd_signal() is used.

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 as:

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.

PARAMETERS

sig: Is the signal number for which the signal is to be installed.
func: Is the signal handler function, declared as shown above.

RETURN VALUES

On success, bsd_signal() returns the previous action for sig. Otherwise, SIG_ERR is returned, and errno is set to one of the following values:

EINVAL: The value of sig is an invalid or unsupported signal number, or bsd_signal() attempted to catch a signal that cannot be caught, or the function tried to ignore a signal that cannot be ignored.

bsd_signal()
replacement for BSD signal() function

Function

SYNOPSIS

DESCRIPTION

PARAMETERS

RETURN VALUES

CONFORMANCE

MULTITHREAD SAFETY LEVEL

PORTING ISSUES

AVAILABILITY

SEE ALSO

bsd_signal() replacement for BSD signal() function

Function

bsd_signal()
replacement for BSD signal() function