File: libc.info,  Node: Blocking in BSD,  Prev: BSD Handler,  Up: BSD Signal Ha\ndling

BSD Functions for Blocking Signals
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 - Macro: int sigmask (int SIGNUM)
     This macro returns a signal mask that has the bit for signal SIGNUM
     set.  You can bitwise-OR the results of several calls to `sigmask'
     together to specify more than one signal.  For example,

          (sigmask (SIGTSTP) | sigmask (SIGSTOP)
           | sigmask (SIGTTIN) | sigmask (SIGTTOU))

     specifies a mask that includes all the job-control stop signals.

 - Function: int sigblock (int MASK)
     This function is equivalent to `sigprocmask' (*note Process Signal
     Mask::.) with a HOW argument of `SIG_BLOCK': it adds the signals
     specified by MASK to the calling process's set of blocked signals.
     The return value is the previous set of blocked signals.

 - Function: int sigsetmask (int MASK)
     This function equivalent to `sigprocmask' (*note Process Signal
     Mask::.) with a HOW argument of `SIG_SETMASK': it sets the calling
     process's signal mask to MASK.  The return value is the previous
     set of blocked signals.

 - Function: int sigpause (int MASK)
     This function is the equivalent of `sigsuspend' (*note Waiting for
     a Signal::.):  it sets the calling process's signal mask to MASK,
     and waits for a signal to arrive.  On return the previous set of
     blocked signals is restored.


