OK, here's the deal:
Src box:
Prod server running FreeBSD 4.9-STABLE, perl 5.005_03
Tgt box:
Linux (RH FC3) kernel 2.6.9, perl v5.8.5

Src is sending concatenated long doubles:
                $s.= pack('D',$count{$ip}{$x}{in});
                $s.= pack('D',$count{$ip}{$x}{out});
                $s.= pack('D',int $count{$ip}{$x}{in});
                $s.= pack('D',int $count{$ip}{$x}{out});
                $s.= pack('D',int $count{$ip}{$x}{inpackets});
                $s.= pack('D',int $count{$ip}{$x}{outpackets});

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This cannot be changed as many boxes depend already on output.

Tgt unpacks:
unpack('d',substr($msg,$ptr,8));
unpack('d',substr($msg,$ptr+8,8));
unpack('d',substr($msg,$ptr+16,8));
unpack('d',substr($msg,$ptr+24,8));

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Obviously sometimes the incoming num is too big and corruption occurs. Perldoc on tgt says:

    D   A long double-precision float in the native format.
        (Long doubles are available only if your system   
         supports long double values _and_ if Perl has been 
         compiled to support those.
         Causes a fatal error otherwise.)

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Tgt box has not been recompiled.
Qn: will RH FC3 support long doubles if we try to re-compile?
We would prefer not to re-compile if possible, as tgt is prod box also.
Is it possible to unpack using a different method eg unpack each block of 8 bytes as 2 sets of 4, then re-combine?
Thx for any help
Chris

In reply to Value packed as 'D', how to unpack not using 'D'? by chrism01

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