On Sun, Jul 25, 2010 at 04:54:53PM -0400, Chet Ramey wrote: > On 7/25/10 8:51 AM, Julien Dessaux wrote: > > I have a script that trap USR1 for reloading purpose. The signal handler > > then does some cleaning, then exec $0. > > With BSD and Posix-style signals, the caught signal is automatically > blocked by the kernel when executing its signal handler. If you exec > a new program out of the signal handler, it's going to be executed > with that signal blocked. From the new program's perspective, it really > is as if you never left the signal handler.
I believe the typical workaround for this type of issue is to set a variable in the signal handler, and then (outside the trap, in some sort of main loop) check for that variable and do the real handling. I've never developed a bash script that needed that sort of sophistication, but that's how it's generally done in C.
