Error in C example
The C example uses
printf in the signal handler. However, printf isn't signal-safe, that is, if the signal happens during the printf call in the main program, it might fail. The correct way would be to set a flag of type
volatile sig_atomic_t in the signal handler, and test that flag in the main program. Note that usleep returns when interrupted by a signal, so handling of that signal will not be delayed that way. --Ce 08:38, 31 March 2009 (UTC)==
Many poor examples
Many of these examples demonstrate a very poor algorithm for the case of user initiated signals ( INT, QUIT, INFO...), Specifically those that set a flag within the signal handler and then exiting the signal handler (taking no other action).
If the code within the looping construct gets stuck in a (nearly) infinite loop, the test of the flag will not be performed.