Types of signals in Linux

Signal	Value	Description
Sighup	1	Hangup (POSIX) Report that user's terminal is disconnected. signal used to report the termination of the controlling process.
SIGINT	2	Interrupt (ANSI) Program interrupt. (CTRL-C)
Sigquit	3	Quit (POSIX) Terminate process and generate core dump.
Sigill	4	Illegal instruction (ANSI) Generally indicates that the executable file is already upted or use of data where a pointer to a function was expected.
Sigtrap	5	Trace trap (POSIX)
SIGABRT Sigiot	6	Abort (ANSI) Iot trap (4.2 BSD) Process detects error and reports by calling abort
Sigbus	7	Bus Error (4.2 BSD) Indicates an access to an Invalid Address.
Sigfpe	8	Floating-point Arithmetic exception (ANSI ). This includes des division by zero and overflow. the IEEE Standard for binary floating-point Arithmetic (ANSI/IEEE Std 754-1985) defines various floating-point exceptions.
Sigkill	9	Kill, unblockable (POSIX) Cause immediate program termination. Can not be handled, blocked or ignored.
SIGUSR1	10	User-Defined signal 1
SIGSEGV	11	Segmentation violation (ANSI) Occurs when a program tries to read or write outside the memory that is allocated for it by the operating system, dereferencing a bad or NULL pointer. indicates an invalid access to valid memory.
Sigusr2	12	User-Defined Signal 2
Sigpipe	13	Broken pipe (POSIX) Error condition like trying to write to a socket which is not connected.
Sigalrm	14	Alarm clock (POSIX) Indicates expiration of a timer. Used byAlarm ()Function.
Sigterm	15	Termination (ANSI) This signal can be blocked, handled, and ignored. generated by "kill" command.
Sigstkflt	16	Stack fault
Sigchld Sigcld	17	Child status has changed (POSIX) Signal sent to parent process whenever one of its child processes terminates or stops. See the yolinux.com fork, exec, wait, waitpid tutorial
Sigcont	18	Continue (POSIX) Signal sent to process to make it continue.
Sigstop	19	Stop, unblockable (POSIX) Stop a process. This signal cannot be handled, ignored, or blocked.
Sigtstp	20	Keyboard stop (POSIX) Interactive stop signal. This signal can be handled and ignored. (CTRL-Z)
Sigttin	21	Background read from tty (POSIX)
Sigttou	22	Background write to TTY (POSIX)
Sigurg	23	Urgent condition on socket (4.2 BSD) Signal sent when "urgent" or out-of-band data arrives on a socket.
Sigxcpu	24	CPU limit exceeded (4.2 BSD)
Sigxfsz	25	File size limit exceeded (4.2 BSD)
Sigvtalrm	26	Virtual time alarm (4.2 BSD) Indicates expiration of a timer.
Sigprof	27	Profiling alarm clock (4.2 BSD) Indicates expiration of a timer. Use for code profiling facilities.
Sigwinch	28	Window Size Change (4.3 BSD, Sun)
Sigio Sigpoll	29	I/O now possible (4.2 BSD) Pollable event occurred (System V) Signal sent when file descriptor is ready to perform I/O (generated by sockets)
Sigpwr	30	Power failure restart (System V)
Sigsys	31	Bad system call

See:/Usr/include/bits/SIGNUM. h

From: http://www.yolinux.com/TUTORIALS/C++Signals.html