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There are several ways to invoke a programm. One of the main differences is in the returning value.
  • system("wc -l");
    Will call the given command and return the return value of that command. This is usually not what you want, because most of the times wc -l will mean that you want to get the number of lines back from that call and not if that call was successful or not.
  • $nol = `wc -l`
    The backticks call the command and return it's output into the variable (here $nol. In this case this will be what you want.
  • Another way of doing this is to use
    $nol = qx/wc -l/;
    (mnemonic: qx quote execute). I think is just the same as the backquotes (at least I don't know any difference)
  • Of course there are other ways (exec,fork) that behave different with respect to processes, but I don't know much about this
Hope this helps...

In reply to Re: how to invoke unix commands in perl by stefan k
in thread how to invoke unix commands in perl by Anonymous Monk

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