anybody with experience using the wait() function?

This is a discussion on anybody with experience using the wait() function? within the C Programming forums, part of the General Programming Boards category; I'm working on a program that forks into several processes. The main process becomes a server, and the child processes ...

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    anybody with experience using the wait() function?

    I'm working on a program that forks into several processes. The main process becomes a server, and the child processes become clients. The clients basically request line numbers to a file until a certain limit is reached, and the server then quits. My problem is that as soon as the server reaches it's limit, it exits and the child processes also exit without printing out what they accomplished. When I try using the wait function, the system just hangs.
    I've tried using wait with the process ids as well. Am I missing something when I'm working with the wait function? Any ideas? Thanks.

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    Seems to me that your clients need to make a better job of detecting that the server has quit, rather than just quitting themselves in response.

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    You're probably right.. any ideas on how to set the client up to realize when the server has completed? Thanks.

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    Look at the error status from reading the pipe (assuming you're using pipes).

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    I'm using pipes.. how can I check on the error status? First time using c.. actually, first time working between processes like this. Thanks for the help.

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    > how can I check on the error status?
    RTFM would be a start - you must have done quite a lot of reading to get this far, just keep digging.

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    Well, I have been looking at the manual.. or on-line references, for that matter. I've been using the unix man cmds to try to find stuff. One of the clients closes up shop, and the server does too.. it's the other 2 clients that are left hanging around. Supposedly the read/write functions are supposed to return back with a negative value if they fail? Is that correct?

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    That would be my first guess
    read is the only thing you're likely to be doing to a pipe when it's suddenly closed.

    Code:
    n = read( ... );
    if ( n == -1 ) {
      perror("read error");
    }
    Find out which error number is associated with the closure of the pipe, then code this in.

    You should still report any other read error as being unusual.

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