in reply to Re^3: how can I detach a thread from another or how can I set a timer for a thread?
in thread how can I detach a thread from another or how can I set a timer for a thread?

Thanks a lot, it works for me. May I bother you with another question? I saw some code like:

$pid = open my $fh, "$cmd |" or die "$!, $^E";

Could you please tell me what does it mean by '$^E'

I　google it, but nothing useful.

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Re^5: how can I detach a thread from another or how can I set a timer for a thread?
by zentara (Cardinal) on Nov 15, 2011 at 11:13 UTC
    It's a built-in error message. Read perldoc perlvars and read the section on Error Variables. Its says: 
     $EXTENDED_OS_ERROR
       $^E     Error information specific to the current operating system. At the moment, this differs from $! under only VMS, OS/2, and
               Win32 (and for MacPerl). On all other platforms, $^E is always just the same as $!.

               Under VMS, $^E provides the VMS status value from the last system error. This is more specific information about the last
               system error than that provided by $!. This is particularly important when $!  is set to EVMSERR.

               Under OS/2, $^E is set to the error code of the last call to OS/2 API either via CRT, or directly from perl.

               Under Win32, $^E always returns the last error information reported by the Win32 call "GetLastError()" which describes the
               last error from within the Win32 API. Most Win32-specific code will report errors via $^E. ANSI C and Unix-like calls set
               "errno" and so most portable Perl code will report errors via $!.

               Caveats mentioned in the description of $! generally apply to $^E, also.

               This variable was added in Perl 5.003.

               Mnemonic: Extra error explanation.
    I'm not really a human, but I play one on earth.
    Old Perl Programmer Haiku ................... flash japh
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Re^5: how can I detach a thread from another or how can I set a timer for a thread?
by Anonymous Monk on Nov 15, 2011 at 11:15 UTC

    I　google it, but nothing useful.

    [ddg://"$^E" site:perl.org] -> "$^E" site:perl.org

    [google://"$^E" site:perl.org] -> "$^E" site:perl.org

    [google://"$^E" site:cpan.org] -> "$^E" site:cpan.org

    [perldoc://"$^E"] -> "$^E"

    Yeah, google seems to have gotten crappier, meh 

    perldoc -v "$^E"
    $EXTENDED_OS_ERROR
    $^E     Error information specific to the current operating system
+. At
...

    [download]

    $ perldoc perltoc |grep "\^E"
            , $COMPILING, $^C , $DEBUGGING, $^D , ${^ENCODING} , %ENV 
+,
            ${^CHILD_ERROR_NATIVE} , $EXTENDED_OS_ERROR, $^E ,
        $^E is meaningful on Win32
            $^E, $^H, $^M
        %ENV, CRTL_ENV, CLISYM_[LOCAL], Any other string, $!, $^E, $?,
+ $|

    [download]

    [doc://perlvar#$^E] -> $^E

    You cant go wrong with a classic :) Tutorials: How to RTFM

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