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sigvec(2)
NAME
  sigvec - Provide a compatibility interface to the sigaction() function

SYNOPSIS
  #include <sys/signal.h>

  int sigvec(
	  int signal,
	  struct sigvec *in_vec,
	  struct sigvec *out_vec );

PARAMETERS
  signal  Specifies the signal number.

  in_vec  Points to a sigvec structure that specifies the action to be taken
	  when the specified signal is delivered, the mask to be used when
	  calling the signal handler, and the flags that modify signal
	  behavior.

  out_vec Points to a sigvec structure that is set to the previous signal
	  action state on successful return from the sigvec() function.

DESCRIPTION
  The sigvec() function is provided for compatibility with old UNIX systems;
  its function is a subset of the operations available with the sigaction()
  function. Like the sigaction() function, the sigvec() function allows the
  user to set the action to take upon the receipt of a signal and to specify
  a signal handler mask to block signals before calling the signal handler.
  However, only signals with values 1 to 31 can be masked on entry to a
  signal-handler set up with the sigvec() function.

  The sigvec structure has the following members:

       void (*sv_handler)();
       int   sv_mask;
       int   sv_flags;

  The sv_handler field specifies the action for the signal, and can be
  SIG_DFL, SIG_IGN, or the address of a signal handler function. See the
  sigaction() function for a detailed description of the signal actions.

  The sv_mask field specifies a mask which specifies signals to block (in
  addition to any signals already blocked at time of delivery) when the
  signal handler function is called for the signal.  Signal i is blocked if
  the i-th bit of the mask is set. Only signals with values 1 to 31 can be
  masked with the sigvec() function. The sv_flags field contains flags that
  further specify signal behavior. If SV_ONSTACK is set, the signal handler
  runs on the signal stack specified by the sigstack() function; otherwise,
  the signal handler runs on the stack of the process receiving the signal.
  If SV_INTERRUPT is set, a system call that is interrupted by signal returns
  a value of -1 with errno set to [EINTR]; otherwise, a system call
  interrupted by signal is restarted.

  If the value of the in_vec parameter is a null pointer, then the signal
  handler information is not set. If the value of the out_vec parameter is
  null, then the previous signal handler information is not returned.

  Once a signal handler is assigned, it remains assigned until another call
  to sigvec() is made or a call is made to signal(), sigaction() or one of
  the exec functions.

NOTES
  The sigvec() function is provided for compatibility only, and its use is
  not recommended. Programs should use the sigaction() function instead.

  The sigvec() function does not check the validity of the sv_handler field
  pointer. If it points to a location outside of the process address space,
  the process receives a memory fault when the system attempts to call the
  signal handler. If the sv_handler field points to anything other than a
  function, the results are unpredictable.

  The signal-handler function can be declared as follows:

  void handler (
	  int signal );

RETURN VALUES
  Upon successful completion, a value of 0 (zero) is returned. If the
  sigvec() function fails, a value of -1 is returned and errno is set to
  indicate the error.

ERRORS
  If the sigvec() function fails, no new signal handler is installed and
  errno may be set to one of the following values:

  [EFAULT]
	  The in_vec or out_vec parameter points to a location outside of the
	  process' address space.

  [EINVAL]
	  The signal parameter is not a valid signal number or an attempt was
	  made to ignore or supply a handler for the SIGKILL signal.

SEE ALSO
  Functions: kill(2), ptrace(2), sigaction(2), sigblock(2), sigpause(3),
  sigstack(2)

Index for Section 2

Alphabetical listing for S

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