On RedHat, the values of the constants are:
Signal SIGHUP = 1
Signal SIGINT = 2
Signal SIGQUIT = 3
Signal SIGILL = 4
Signal SIGTRAP = 5
Signal SIGABRT = 6
Signal SIGIOT = 6
Signal SIGBUS = 7
Signal SIGFPE = 8
Signal SIGUSR1 = 10
Signal SIGSEGV = 11
Signal SIGUSR2 = 12
Signal SIGPIPE = 13
Signal SIGALRM = 14
Signal SIGTERM = 15
Signal SIGSTKFLT = 16
Signal SIGCLD = 17
Signal SIGCHLD = 17
Signal SIGCONT = 18
Signal SIGTSTP = 20
Signal SIGTTIN = 21
Signal SIGTTOU = 22
Signal SIGURG = 23
Signal SIGXCPU = 24
Signal SIGXFSZ = 25
Signal SIGVTALRM = 26
Signal SIGPROF = 27
Signal SIGWINCH = 28
Signal SIGPOLL = 29
Signal SIGIO = 29
Signal SIGPWR = 30
Signal SIGSYS = 31
Signal SIGBABY = 31
Signal SIG_BLOCK = 0
Signal SIG_UNBLOCK = 1
Signal SIG_SETMASK = 2