sigaction.h

它通过提供glibc兼容使得应用程序移植到较小的c 库时相当得容易. 它能够应用到带虚拟存储的Linux和uClinux上.在大多数带MMU部件的平台上为使它更加紧凑,它也能够编译成共享库.uClib

/* The proper definitions for Linux/SPARC sigaction.
   Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, write to the Free
   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307 USA.  */

#ifndef _SIGNAL_H
# error "Never include <bits/sigaction.h> directly; use <signal.h> instead."
#endif

/* Structure describing the action to be taken when a signal arrives.  */
struct sigaction
  {
    /* Signal handler. */
#ifdef __USE_POSIX199309
    union
      {
	/* Used if SA_SIGINFO is not set.  */
	__sighandler_t sa_handler;
	/* Used if SA_SIGINFO is set.  */
	void (*sa_sigaction) (int, siginfo_t *, void *);
      }
    __sigaction_handler;
# define sa_handler	__sigaction_handler.sa_handler
# define sa_sigaction	__sigaction_handler.sa_sigaction
#else
    __sighandler_t sa_handler;
#endif

    /* Additional set of signals to be blocked.  */
    __sigset_t sa_mask;

    /* Special flags.  */
    unsigned long sa_flags;

    /* Not used by Linux/Sparc yet.  */
    void (*sa_restorer) (void);
  };


/* Bits in `sa_flags'.  */
#define	SA_NOCLDSTOP 0x00000008  /* Don't send SIGCHLD when children stop.  */
#define SA_NOCLDWAIT 0x00000100  /* Don't create zombie on child death.  */
#define SA_SIGINFO   0x00000200  /* Invoke signal-catching function with
				    three arguments instead of one.  */
#if defined __USE_UNIX98 || defined __USE_MISC
# define SA_ONSTACK   0x00000001 /* Use signal stack by using `sa_restorer'. */
# define SA_RESTART   0x00000002 /* Restart syscall on signal return.  */
# define SA_INTERRUPT 0x00000010 /* Historical no-op.  */
# define SA_NOMASK    0x00000020 /* Don't automatically block the signal when
				    its handler is being executed.  */
# define SA_ONESHOT   0x00000004 /* Reset to SIG_DFL on entry to handler.  */

/* Some aliases for the SA_ constants.  */
# define SA_NODEFER   SA_NOMASK
# define SA_RESETHAND SA_ONESHOT
# define SA_STACK     SA_ONSTACK
#endif

/* Values for the HOW argument to `sigprocmask'.  */
#define	SIG_BLOCK     1		 /* Block signals.  */
#define	SIG_UNBLOCK   2		 /* Unblock signals.  */
#define	SIG_SETMASK   4		 /* Set the set of blocked signals.  */