.\" Copyright (c) 1983, 1991 The Regents of the University of California.
.\" %sccs.include.redist.man%
.\" @(#)sigprocmask.2 6.3 (Berkeley) %G%
.Nd manipulate current signal mask
.Fn sigprocmask "int how" "const sigset_t *set" "sigset_t *oset"
function examines and/or changes the current signal mask (those signals
that are blocked from delivery).
Signals are blocked if they are members of the current signal mask set.
is not null, the action of
depends on the value of the parameter
The signal mask is changed as a function of the specified
The function is specified by
using one of the following values from
.Bl -tag -width SIG_UNBLOCK
The new mask is the union of the current mask and the specified
The new mask is the intersection of the current mask
and the complement of the specified
The current mask is replaced by the specified
is not null, it is set to
the previous value of the signal mask.
is insignificant and the mask remains unset
providing a way to examine the signal mask without modification.
A 0 value indicated that the call succeeded. A -1 return value
indicates an error occurred and
is set to indicated the reason.
call will fail and the signal mask will be unchanged if one
.Bl -tag -width Bq Er EINVAL
has a value other than those listed here.
function call is expected to
conform to IEEE Std 1003.1-1988