#include <signum.h> // /usr/include/bits/signum.h
#define SIGHUP 1 /* [T] Hangup (POSIX). */
#define SIGINT 2 /* [T] Interrupt (ANSI). */
#define SIGQUIT 3 /* [A] Quit (POSIX). */
#define SIGILL 4 /* [A] Illegal instruction (ANSI). */
#define SIGTRAP 5 /* [A] Trace trap (POSIX). */
#define SIGABRT 6 /* [A] Abort (ANSI). */
#define SIGIOT 6 /* IOT trap (4.2 BSD). */
#define SIGBUS 7 /* [A] BUS error (4.2 BSD). */
#define SIGFPE 8 /* [A] Floating-point exception (ANSI). */
#define SIGKILL 9 /* [T] Kill, unblockable (POSIX). */
#define SIGUSR1 10 /* [T] User-defined signal 1 (POSIX). */
#define SIGSEGV 11 /* [A] Segmentation violation (ANSI). */
#define SIGUSR2 12 /* [T] User-defined signal 2 (POSIX). */
#define SIGPIPE 13 /* [T] Broken pipe (POSIX). */
#define SIGALRM 14 /* [T] Alarm clock (POSIX). */
#define SIGTERM 15 /* [T] Termination (ANSI). */
#define SIGSTKFLT 16 /* Stack fault. */
#define SIGCHLD 17 /* [I] Child status has changed (POSIX). */
#define SIGCONT 18 /* [C] Continue (POSIX). */
#define SIGSTOP 19 /* [S] Stop, unblockable (POSIX). */
#define SIGTSTP 20 /* [S] Keyboard stop (POSIX). */
#define SIGTTIN 21 /* [S] Background read from tty (POSIX). */
#define SIGTTOU 22 /* [S] Background write to tty (POSIX). */
#define SIGURG 23 /* [I] Urgent condition on socket (4.2 BSD). */
#define SIGXCPU 24 /* [A] CPU limit exceeded (4.2 BSD). */
#define SIGXFSZ 25 /* [A] File size limit exceeded (4.2 BSD). */
#define SIGVTALRM 26 /* [T] Virtual alarm clock (4.2 BSD). */
#define SIGPROF 27 /* [T] Profiling alarm clock (4.2 BSD). */
#define SIGWINCH 28 /* Window size change (4.3 BSD, Sun). */
#define SIGPOLL 29 /* [T] Pollable event occurred (System V). */
#define SIGIO 29 /* [T] I/O now possible (4.2 BSD). */
#define SIGPWR 30 /* Power failure restart (System V). */
#define SIGSYS 31 /* [A] Bad system call. */
#define SIGUNUSED 31