usr/include/signal.h

#ifndef NSIG
#define NSIG    32

#define SIGHUP  1       /* hangup */
#define SIGINT  2       /* interrupt */
#define SIGQUIT 3       /* quit */
#define SIGILL  4       /* illegal instruction (not reset when caught) */
#define SIGTRAP 5       /* trace trap (not reset when caught) */
#define SIGIOT  6       /* IOT instruction */
#define SIGEMT  7       /* EMT instruction */
#define SIGFPE  8       /* floating point exception */
#define         K_INTOVF 1      /* integer overflow */
#define         K_INTDIV 2      /* integer divide by zero */
#define         K_FLTOVF 3      /* floating overflow */
#define         K_FLTDIV 4      /* floating/decimal divide by zero */
#define         K_FLTUND 5      /* floating underflow */
#define         K_DECOVF 6      /* decimal overflow */
#define         K_SUBRNG 7      /* subscript out of range */
#define SIGKILL 9       /* kill (cannot be caught or ignored) */
#define SIGBUS  10      /* bus error */
#define SIGSEGV 11      /* segmentation violation */
#define SIGSYS  12      /* bad argument to system call */
#define SIGPIPE 13      /* write on a pipe with no one to read it */
#define SIGALRM 14      /* alarm clock */
#define SIGTERM 15      /* software termination signal from kill */

#define SIGSTOP 17      /* sendable stop signal not from tty */
#define SIGTSTP 18      /* stop signal from tty */
#define SIGCONT 19      /* continue a stopped process */
#define SIGCHLD 20      /* to parent on child stop or exit */
#define SIGTTIN 21      /* to readers pgrp upon background tty read */
#define SIGTTOU 22      /* like TTIN for output if (tp->t_local&LTOSTOP) */
#define SIGTINT 23      /* to pgrp on every input character if LINTRUP */
#define SIGXCPU 24      /* exceeded CPU time limit */
#define SIGXFSZ 25      /* exceeded file size limit */

#ifndef KERNEL
int     (*signal())();
#endif

#define BADSIG          (int (*)())-1
#define SIG_DFL         (int (*)())0
#define SIG_IGN         (int (*)())1
#ifdef KERNEL
#define SIG_CATCH       (int (*)())2
#endif
#define SIG_HOLD        (int (*)())3

#define SIGISDEFER(x)   (((int)(x) & 1) != 0)
#define SIGUNDEFER(x)   (int (*)())((int)(x) &~ 1)
#define DEFERSIG(x)     (int (*)())((int)(x) | 1)

#define SIGNUMMASK      0377            /* to extract pure signal number */
#define SIGDOPAUSE      0400            /* do pause after setting action */
#define SIGDORTI        01000           /* do ret+rti after setting action */
#endif