SSIGNAL(3)

NAME
ssignal, gsignal - software signals

SYNOPSIS
#include <signal.h>

int (*ssignal (sig, action))()
int sig, (*action)();

int gsignal (sig)
int sig;

DESCRIPTION

ssignal() and ssignal() implement a software facility similar to signal(3V).

Software signals made available to users are associated with integers in the inclusive range 1 through 15. A call to ssignal() associates a procedure, action, with the software signal sig; the software signal, sig, is raised by a call to ssignal(). Raising a software signal causes the action established for that signal to be taken.

The first argument to ssignal() is a number identifying the type of signal for which an action is to be established. The second argument defines the action; it is either the name of a (user-defined) action function or one of the manifest constants SIG_DFL (default)or SIG_IGN (ignore). ssignal() returns the action previously established for that signal type; if no action has been established or the signal number is illegal, ssignal() returns SIG_DFL.

ssignal() raises the signal identified by its argument, sig:

    If an action function has been established for sig, then that action is reset to SIG_DFL and the action function is entered with argument sig. ssignal() returns the value returned to it by the action function.

    If the action for sig is SIG_IGN, ssignal() returns the value 1 and takes no other action.

    If the action for sig is SIG_DFL, ssignal() returns the value 0 and takes no other action.

    If sig has an illegal value or no action was ever specified for sig, ssignal() returns the value 0 and takes no other action.

SEE ALSO
signal(3V)