Python signal amount

The concept of signal

Signal (signal) - The way of communication between processes is a software interrupt. Once a process receives a signal, it interrupts the original program execution flow to handle the signal.

Several common signals:

SIGINT                                                                                   use using using using using using using using using   out out out out out off out out out out out out out out out of ‐ in ‐ ‐ ‐SIGINT ​                                  SIGALRM alarm clock signal

For example, if you want to do some processing when pressing control+c to terminate the process, the code is as follows:

import signal

def fun(sig, stack_frame):

　print 'eixt %d, %s' % ( sig,stack_frame)

　exit(1)

signal.signal(signal.SIGINT, fun)

signal.signal(signal.SIGINT, fun) is used to register the processing function of the semaphore,

the first parameter It is a semaphore. The second parameter can be passed to a function. This function has two parameters by default. The first parameter sig represents the received semaphore. The second stack_frame can be understood as the call stack that generates the interrupt semaphore sig. .