System Calls Manual
NAME sigpending — get pending signals
LIBRARY Standard C Library (libc, -lc)
SYNOPSIS #include <signal.h>
DESCRIPTION The sigpending function returns a mask of the signals pending for delivery to the calling process in the location indicated by set. Signals may be pending because they are currently masked, or they are in transition before delivery (although the latter case is not normally detectable).
RETURN VALUES A 0 value indicates that the call succeeded. A -1 return value indicates an error occurred and errno is set to indicate the reason.
() will fail if:
set specifies an invalid address.
STANDARDS The sigpending function conforms to IEEE Std 1003.1-1990 (“POSIX.1”).