Messages in this thread | | | Date | Wed, 22 Dec 1999 08:27:28 -0500 (EST) | From | "Richard B. Johnson" <> | Subject | Re: Strange piece of code |
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On Wed, 22 Dec 1999, Giovanni Picoli Tirloni wrote:
> Hi, I was having a tour in the kernel sources and I found some codes > that I can't understand why. Like this in ppp: > > int > ppp_init (struct device *dev) > { > static int first_time = 1; <== define to 1 > int answer = 0; > > if (first_time) { <== check if is 1, why ? any special special reason? > first_time = 0; > answer = ppp_first_time(); > if (answer == 0) > (void) register_symtab (&ppp_syms); > } > if (answer == 0) > answer = -ENODEV; > return answer; > } > > I found many more codes like this in the source, I cant remeber where anymore. >
first_time is "static". It is initialized to "true" once. Then, the first time the code executes, it is set to "false". From that time on, and ever forevermore, the "first_time" code will not be executed again.
Cheers, Dick Johnson
Penguin : Linux version 2.3.13 on an i686 machine (400.59 BogoMips). Warning : The end of the world as we know it requires a new calendar. Seconds : 833552 (until Y2K)
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