参见文件：/usr/include/bits/signum.h

/* Signal number definitions.  Linux version.Copyright (C) 1995-2013 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/ormodify it under the terms of the GNU Lesser General PublicLicense as published by the Free Software Foundation; eitherversion 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 ofMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNULesser General Public License for more details.You should have received a copy of the GNU Lesser General PublicLicense along with the GNU C Library; if not, see<http://www.gnu.org/licenses/>.  */#ifdef	_SIGNAL_H/* Fake signal functions.  */
#define SIG_ERR	((__sighandler_t) -1)		/* Error return.  */
#define SIG_DFL	((__sighandler_t) 0)		/* Default action.  */
#define SIG_IGN	((__sighandler_t) 1)		/* Ignore signal.  */#ifdef __USE_UNIX98
# define SIG_HOLD	((__sighandler_t) 2)	/* Add signal to hold mask.  */
#endif/* Signals.  */
#define	SIGHUP		1	/* Hangup (POSIX).  */
#define	SIGINT		2	/* Interrupt (ANSI).  */
#define	SIGQUIT		3	/* Quit (POSIX).  */
#define	SIGILL		4	/* Illegal instruction (ANSI).  */
#define	SIGTRAP		5	/* Trace trap (POSIX).  */
#define	SIGABRT		6	/* Abort (ANSI).  */
#define	SIGIOT		6	/* IOT trap (4.2 BSD).  */
#define	SIGBUS		7	/* BUS error (4.2 BSD).  */
#define	SIGFPE		8	/* Floating-point exception (ANSI).  */
#define	SIGKILL		9	/* Kill, unblockable (POSIX).  */
#define	SIGUSR1		10	/* User-defined signal 1 (POSIX).  */
#define	SIGSEGV		11	/* Segmentation violation (ANSI).  */
#define	SIGUSR2		12	/* User-defined signal 2 (POSIX).  */
#define	SIGPIPE		13	/* Broken pipe (POSIX).  */
#define	SIGALRM		14	/* Alarm clock (POSIX).  */
#define	SIGTERM		15	/* Termination (ANSI).  */
#define	SIGSTKFLT	16	/* Stack fault.  */
#define	SIGCLD		SIGCHLD	/* Same as SIGCHLD (System V).  */
#define	SIGCHLD		17	/* Child status has changed (POSIX).  */
#define	SIGCONT		18	/* Continue (POSIX).  */
#define	SIGSTOP		19	/* Stop, unblockable (POSIX).  */
#define	SIGTSTP		20	/* Keyboard stop (POSIX).  */
#define	SIGTTIN		21	/* Background read from tty (POSIX).  */
#define	SIGTTOU		22	/* Background write to tty (POSIX).  */
#define	SIGURG		23	/* Urgent condition on socket (4.2 BSD).  */
#define	SIGXCPU		24	/* CPU limit exceeded (4.2 BSD).  */
#define	SIGXFSZ		25	/* File size limit exceeded (4.2 BSD).  */
#define	SIGVTALRM	26	/* Virtual alarm clock (4.2 BSD).  */
#define	SIGPROF		27	/* Profiling alarm clock (4.2 BSD).  */
#define	SIGWINCH	28	/* Window size change (4.3 BSD, Sun).  */
#define	SIGPOLL		SIGIO	/* Pollable event occurred (System V).  */
#define	SIGIO		29	/* I/O now possible (4.2 BSD).  */
#define	SIGPWR		30	/* Power failure restart (System V).  */
#define SIGSYS		31	/* Bad system call.  */
#define SIGUNUSED	31#define	_NSIG		65	/* Biggest signal number + 1(including real-time signals).  */#define SIGRTMIN        (__libc_current_sigrtmin ())
#define SIGRTMAX        (__libc_current_sigrtmax ())/* These are the hard limits of the kernel.  These values should not beused directly at user level.  */
#define __SIGRTMIN	32
#define __SIGRTMAX	(_NSIG - 1)#endif	/* <signal.h> included.  */