() function returns a mask of the
signals pending for delivery to the calling process in the location indicated
. Signals may be pending because they
are currently masked, or transiently before delivery (although the latter case
is not normally detectable).
Upon successful completion, the value 0 is returned; otherwise the
value -1 is returned and the global variable
is set to indicate the error.
() function does not currently detect
() function is defined by
IEEE Std 1003.1-2008