Linux supports the standard signals listed below.
Types of signals:
Report that user’s terminal is disconnected. Signal used to report the termination of the controlling process.
Program interrupt. (ctrl-c)
Terminate process and generate core dump.
|SIGILL||4||Illegal Instruction (ANSI)|
Generally indicates that the executable file is corrupted or use of data where a pointer to a function was expected.
|SIGTRAP||5||Trace trap (POSIX)|
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 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 by the alarm() function.
This signal can be blocked, handled, and ignored. Generated by «kill» command.
|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
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)|
|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|