List of common kill signals

Because freesco uses a stripped down version of the linux kill command, it does not support the kill signals names. This list shows what numeric argument to use if you want to send a specific signal to a running process:

Name Numeric Description
SIGHUP 1 Hang up. If the terminal becomes disconnected from a process, this signal is sent automatically to the process. Sending a process this signal often causes it to reread its configuration files, so it is useful instead of restarting the process. Always check the man page to see if a process has this behavior.
SIGINT 2 Interrupt from keyboard. Issued if you press ctrl-C.
SIGQUIT 3 Quit from keyboard. Issued if you press ctrl-D.
SIGFPE 8 Floating point exception. Issued automatically to a program performing some kind of illegal mathematical operation.
SIGKILL 9 Kill signal. This is one of the signals that can never be caught by a process. If a process gets this signal it must quit immediately and will not perform any clean-up operations (like closing files or removing temporary files). You can send a process a SIGKILL signal if there is no other means of destroying it.
SIGUSR1 10 User signals. These signals are available to developers when they need extra functionality. For example, some processes begin logging debug messages when you send them SIGUSR1.
SIGSEGV 11 Segmentation violation. Issued automatically when a process tries to access memory outside of its allowable address space, equivalent to a Fatal Exception or General Protection Fault under Windows. Note that programs with bugs or programs in the process of being developed often get these signals. A program receiving a SIGSEGV, however, can never cause the rest of the system to be compromised. If the kernel itself were to receive such an error, it would cause the system to come down, but such is extremely rare.
SIGPIPE 13 Pipe died. A program was writing to a pipe, the other end of which is no longer available.
SIGTERM 15 Terminate. Cause the program to quit gracefully.
SIGCHLD 17 Child terminate. Sent to a parent process every time one of its spawned processes dies.

So on FREESCO in order to send a process a SIGHUP signal, you find its PID number with ps command and then type command:

kill -1 12345

where 12345 is the PID from the ps command output.

freesco/howtos/killsignals.txt (80450 views) · Last modified: 2007/01/14 16:38 (external edit)