Обсуждение: Strange behaviour of PL/Perl

Hello All!

I just included PL/Perl language in my database.
Created function:

CREATE FUNCTION and_with_mask(int2, int2) RETURNS int2 AS
'
return $_[0] &
$_[1]
' LANGUAGE 'plperl';


select and_with_mask(4,1);
and_with_mask
---------------
             0

select and_with_mask(8,1);
 and_with_mask
---------------
             0

select and_with_mask(16,1);
 and_with_mask
---------------
             1

select and_with_mask(32,1);
 and_with_mask
---------------
             1

And just in Perl:

#!/usr/bin/perl
    $val = 32 &
1;
    print("val = $val\n");

val = 0

Where am I mistaken or something is in PL/Perl?

--
with respection Andrey Feofilactovich.
e-mail: feo@ttn.ru, feo@feo.org.ru
ICQ: 28073807

"Andrey Y. Mosienko" <feo@ttn.ru> writes:
> I just included PL/Perl language in my database.
> Created function:
> CREATE FUNCTION and_with_mask(int2, int2) RETURNS int2 AS
> [ behaves strangely ]

What Postgres version is this, on what platform?

Does the function behave more reasonably if you declare the
inputs and result as int4?

            regards, tom lane

"Andrey Y. Mosienko" wrote:
>
> Hello All!
>
> I just included PL/Perl language in my database.
> Created function:
>
> CREATE FUNCTION and_with_mask(int2, int2) RETURNS int2 AS
> '
> return $_[0] &
> $_[1]
> ' LANGUAGE 'plperl';

> select and_with_mask(32,1);
>  and_with_mask
> ---------------
>              1

> #!/usr/bin/perl
>     $val = 32 & 1;
>     print("val = $val\n");
>
> val = 0
>
> Where am I mistaken or something is in PL/Perl?

perl -e 'print ("32" & "1"),"\n"'

Values are being passed in as strings so perl is doing bitwise string
operation (perldoc perlop). Convert to numbers by doing +0 or similar.

- Richard Huxton