HP-UX Reference (11i v2 07/12) - 3 Library Functions N-Z (vol 7)

ssignal(3C) ssignal(3C)

NAME

ssignal(), gsignal() - software signals

SYNOPSIS

#include <signal.h>

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

int gsignal(int sig);

DESCRIPTION

ssignal() and gsignal() implement a software facility similar to signal(5). This facility is used by

the Standard C Library to enable users to indicate the disposition of error conditions, and is also made

available to users for their own purposes.

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

gsignal()

. 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 func-

tion 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.

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

• If an action function has been established for sig, that action is reset to SIG_DFL

and the action

function is entered with argument sig.

gsignal() returns the value returned to it by the

action function.

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

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

• If sig has an illegal value or no action was ever speciﬁed for sig,

gsignal() returns the value 0

and takes no other action.