in reply to Re^3: capturing output of system call inside a thread
in thread capturing output of system call inside a thread

Thanks for the reply again.

1. Sorry I was imprecise. I've meant that I want to capture output of the program that is being run by system call: STDOUT and STDERR, as well as STDOUT and STDERR produced by perl code in that "process".

2. You are correct is saying I can't control external program buffering from my perl script. I just want to see in my log file the same thing that I would see on the screen if I were to run that program independently from the command line.

  • Comment on Re^4: capturing output of system call inside a thread

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Re^5: capturing output of system call inside a thread
by BrowserUk (Patriarch) on Sep 03, 2015 at 19:43 UTC
    I want to capture output of the program that is being run by system call: STDOUT and STDERR, as well as STDOUT and STDERR produced by perl code in that "process".

    What is the difference between: output of the program that is being run by system call; and STDOUT and STDERR produced by perl code in that "process"?

    Aren't they the same thing?

    With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
    Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
    "Science is about questioning the status quo. Questioning authority". I knew I was on the right track :)
    In the absence of evidence, opinion is indistinguishable from prejudice.
    I'm with torvalds on this Agile (and TDD) debunked I told'em LLVM was the way to go. But did they listen!
[reply]

      Geez, you guys!

      @BrowserUK: Maybe he means what he said in his first post:

      Each of the worker threads is essentially independent and can run perl code as well as do system() calls.

      @that_guy: Maybe he wanted you to explain specifically what you are doing (e.g. give an example of some of the "perl code" each thread is supposed to run) when he said:

      if you can describe what it is that you need to do; rather than how you are currently trying to do "it"; then I might be able to help

      You're welcome :-) I'm hoping to learn something here . . .

      The way forward always starts with a minimal test.
[reply]

        @1nickt I have submitted code with a minimal example of what I want to do . In reality code that processes are going to run the most general things -- often submitting jobs to sungrid engine or calling standalone programs of which I have no control.

        @BrowserUK I guess I have drawn distinction between STDOUT and STDERR produced by perl code and by program run by system() call because they have shown to behave differently in my example code. Looks like you're suggesting that they should behave the same way. Perhaps they should - I'm not sure. We can go with your assumption that they should. In which case I want to capture STDOUT and STDERR of each worker "process".

[reply]
        Geez, you guys! @BrowserUK: Maybe he means what he said in his first post: Each of the worker threads is essentially independent and can run perl code as well as do system() calls.

        @1nickt.[sic] If you know better; feel free to answer his question. Maybe you can teach me something?

        With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'
        Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.
        "Science is about questioning the status quo. Questioning authority". I knew I was on the right track :)
        In the absence of evidence, opinion is indistinguishable from prejudice.
        I'm with torvalds on this Agile (and TDD) debunked I told'em LLVM was the way to go. But did they listen!
[reply]

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