osx man page for sigpause

SIGPAUSE(2)						      BSD System Calls Manual						       SIGPAUSE(2)

NAME
     sigpause -- atomically release blocked signals and wait for interrupt

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <signal.h>

     int
     sigpause(int sig);

DESCRIPTION
     This interface is made obsolete by sigsuspend(2).

     Sigpause() assigns sig to the set of masked signals and then waits for a signal to arrive; on return the set of masked signals is restored.
     Sig is usually 0, indicating that no signals are to be blocked.  Sigpause() always terminates by being interrupted, returning -1 with errno
     set to EINTR.

COMPATIBILITY
     sigpause() now takes a signal value and not a mask.  This often appears as a hang in sigpause$UNIX2003 or with sigpause() returning with
     errno set to EINVAL.  Use sigsuspend() with signal masks.

SEE ALSO
     kill(2), sigaction(2), sigblock(2), sigprocmask(2), sigsuspend(2), sigvec(2)

HISTORY
     The sigpause() function call appeared in 4.2BSD and has been deprecated.

BSD
								   June 2, 1993 							       BSD