Re: capturing on both interfaces simultaneously

[Guy Harris <guy () alum mit edu>]

On Dec 11, 2011, at 8:36 AM, abhinav narain wrote:

> the return value of error is -1,
> EINTR is 4.

For many UN*X APIs, "the return value" and "the error" are not the same; "the return value" on an error is -1, and "the 
error" is in the variable "errno".

The select() man page on my system (not a Linux distribution, but that doesn't matter, UN*Xes are all the same here) 
says:

RETURN VALUES
     Select() returns the number of ready descriptors that are contained in
     the descriptor sets, or -1 if an error occurred.  If the time limit
     expires, select() returns 0.  If select() returns with an error, includ-
     ing one due to an interrupted call, the descriptor sets will be unmodi-
     fied and the global variable errno will be set to indicate the error.

so it's one of those APIs.

What you should do is to, if select() returns -1 *and* errno is EINTR, just ignore the error and continue looping.

> Also, it keeps printing ": Resource temporarily unavailable"
> though I don't have any error statement to be printed.

What is "it"?  Your program?  Or just *some* program?
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