Implementation of dup2

This is a discussion on Implementation of dup2 within the Linux Programming forums, part of the Platform Specific Boards category; Hi all,I'm reading <Advanced programming in the UNIX environment>,that book asked the reader to implement a function which has same ...

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    Registered User rpbear's Avatar
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    Implementation of dup2

    Hi all,I'm reading <Advanced programming in the UNIX environment>,that book asked the reader to implement a function which has same functions with dup2 without calling fcntl.Could anyone give me a tip?Any help will be appreciated.

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    and the hat of wrongness Salem's Avatar
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    Read what dup2 does, compared to dup (perhaps?)
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

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    Registered User rpbear's Avatar
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    Quote Originally Posted by Salem View Post
    Read what dup2 does, compared to dup (perhaps?)
    The problem is that dup will use the minimum unused file descriptor as the newly open file descriptor.However,without using dup2,how can I make sure that my function will use the specified file descriptor?

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    and the hat of wrongness Salem's Avatar
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    Re-read the previous chapter of the book then for more clues, then try the exercise again?

    Personally, I fail to see the point of "Do x without using the obvious y to achieve the result" type exercises.
    It's like being told how to do a magic trick. The only real fun is figuring it out.
    If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
    If at first you don't succeed, try writing your phone number on the exam paper.
    I support http://www.ukip.org/ as the first necessary step to a free Europe.

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    Registered User rpbear's Avatar
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    Quote Originally Posted by Salem View Post
    Personally, I fail to see the point of "Do x without using the obvious y to achieve the result" type exercises.
    It's like being told how to do a magic trick. The only real fun is figuring it out.
    I do agree with u ^_^

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