Signals are usually defined in /usr/include/signal.h

Avalible sugnals can be listed using:
    # kill -l

---

commonly used signals (may not be set on your machine)

Ctrl-C    INT    SIGINT    Terminate
Ctrl-Z    TSTP    SIGTSTP    suspend
Ctrl-\    ABRT    SIGABRT    simular to INT

---

signaling a PID

    # kill -<signal> PID
or
    # kill -s<signal> PID

---

add much more

---