sig

    The signal to be generated.

 sigcode

    An optional signal code, available only when not compiling in
    strict ANSI C mode. For example, signal SIGFPE-the arithmetic
    trap signal-has 10 different codes, each representing a different
    type of arithmetic trap.

    The signal codes can be represented by mnemonics or numbers. The
    arithmetic trap codes are represented by the numbers 1 to 10;
    the SIGILL codes are represented by the numbers 0 to 2. The code
    values are defined in the <signal.h> header file.