Force blocking read after EAGAIN?

Posted by Daniel Trebbien on Stack Overflow See other posts from Stack Overflow or by Daniel Trebbien
Published on 2010-05-21T23:18:52Z Indexed on 2010/05/21 23:20 UTC
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Filed under:

posix-api

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read

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nonblocking

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file-descriptor

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block

I have a file descriptor that is open for reading which may be non-blocking. What I need to do is simply read all data until reaching EOF and write that data to a writable file descriptor. As the process that performs this copying is not "aware" of anything that is going on around it, I don't think that I can do something useful while waiting for data, and I don't want to use a while loop (while errno is not EAGAIN) because I think that it would be wasteful. Is there a way to block or otherwise suspend execution of the copying process until data becomes available?

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