yangyu has asked for the wisdom of the Perl Monks concerning the following question:

hi monks,
this is the code, array_argument_testing.pl 
#!/usr/bin/perl     
    
  @a=(9,2,3,4);   
  @b=("a","b");   
    
  func(\@a,\@b);   
    
  sub   func   {   
  ($c,$d) = @_;
  print   $#{@$c}+1,$#{@$d}+1;   
  }

[download]
result from run at windows: 
C:\pl>perl array_argument_testing.pl
00

[download]
result from run at unix: 
$ perl array_argument_testing.pl
42

[download]
The result from unix is what I want,but what's the problem that the result is different from windows?

thanks for your help
YangYu

Replies are listed 'Best First'.
Re: same code,run at windows and unix separately,the result is different
by ikegami (Patriarch) on Jun 10, 2009 at 05:21 UTC

    This error that would have been prevented by use strict; use warnings;

    I bet your Windows version is 5.10 and your unix version predates 5.10. 

    >c:\progs\perl588\bin\perl -l 770193.pl
42

>c:\progs\perl589\bin\perl -l 770193.pl
42

>c:\progs\perl5100\bin\perl -l 770193.pl
00

    [download]

    Before 5.10, a bug caused the "@" in "$#{@a}" to be ignored. It was fixed in 5.10.0.

    Fixed: 

    #!/usr/bin/perl     

use strict;
use warnings;

my @a = (9, 2, 3, 4);   
my @b = ("a", "b");   
    
func(\@a, \@b);   
    
sub func {
   my ($c, $d) = @_;
   print $#{$c}+1, $#{$d}+1, "\n";
  #print $#$c+1,   $#$d+1,   "\n";   \
  #print 0+@{$c},  0+@{$d},  "\n";    > Alternatives
  #print 0+@$c,    0+@$d,    "\n";   /
}

    [download]

    See Dereferencing Syntax.

    Update: Added alternatives and link.
    Update: Added results of various version.

[reply]
[d/l]
[select]
Re: same code,run at windows and unix separately,the result is different
by syphilis (Archbishop) on Jun 10, 2009 at 05:25 UTC
    Prints '42' for me on windows, as expected.
    The code being run on Windows must be different to the code being run on linux - otherwise output would be the same.

    Cheers,
    Rob
[reply]

      As expected? The array @4 has zero elements, not four. Similarly, the array @2 has zero elements, not two.

[reply]
[d/l]
[select]
        As expected?

        Correction ... make that "as I expected" .... having not taken the time to look too closely or think too hard about it. (Why wasn't the same bugfix applied to perl 5.8.9 ?)

        Cheers,
        Rob
[reply]

Back to Seekers of Perl Wisdom