in reply to Re^2: A DWIM too far?
in thread A DWIM too far?

As is, the behaviour makes it impossible to safely rename a file.
It makes it harder, at least: 
sub myrename 
{ my $rename = ( $^O eq 'MSWin32' ) ? 'move -y' : 'mv -i';
  `$rename @_[0,1]`;
  return $!;
}
myrename('abc','def') or die $!;

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I can't recall how to do this to the CORE, perhaps someone will remind me?

-QM
--
Quantum Mechanics: The dreams stuff is made of

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Re^4: A DWIM too far?
by ihb (Deacon) on Jun 18, 2004 at 02:22 UTC
    It seems you answered the wrong question. The problem is that you can't be sure to not overwrite a file by renaming it. Your rename subroutine does quite the opposite. Or have I completely misunderstood your reply?
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      I think you misunderstood (at least, I hope I've understood :)

      Rewriting rename to include the -i option (or -y option for Windoze) will not clobber an existing file (unless the underlying OS function has the same problem with the -i option, in which case we're all screwed.)

      I tried my example out, and it seemed to work as I intended. I'm sure someone has come up with a more robust and useful version. I was just trying to show that it was possible.

      -QM
      --
      Quantum Mechanics: The dreams stuff is made of

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        The /Y operator on windows forces it to overwrite without confirmation /-Y forces confirmation and there is no documented way to force failure when a file exists already.


        ___________
        Eric Hodges
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Re^4: A DWIM too far?
by BrowserUk (Patriarch) on Jun 18, 2004 at 01:40 UTC 
    *GLOBAL::CORE::rename = \&myrename;

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    Update: The above is wrong! It should be 

    *CORE::GLOBAL::rename = \&myrename;

    [download]
    Examine what is said, not who speaks.
    "Efficiency is intelligent laziness." -David Dunham
    "Think for yourself!" - Abigail
    "Memory, processor, disk in that order on the hardware side. Algorithm, algoritm, algorithm on the code side." - tachyon
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      Great! Is it possible to say 
      sub *GLOBAL::CORE::rename {...}

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      directly? Or is it a two step process?

      -QM
      --
      Quantum Mechanics: The dreams stuff is made of

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        Actually, I got the CORE and GLOBAL the wrong way around. It should be

        *GLOBAL::CORE::rename = \&myrename;

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        Or to do it in one step something like

        sub CORE::GLOBAL::rename{ 
    system "ren $_[ 0 ], $_[ 1 ]"; 
    return $? >> 8; 
}

        [download]
        Examine what is said, not who speaks.
        "Efficiency is intelligent laziness." -David Dunham
        "Think for yourself!" - Abigail
        "Memory, processor, disk in that order on the hardware side. Algorithm, algoritm, algorithm on the code side." - tachyon
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In Section Meditations