Re: how are these two strings not equal?

From: Kev <[email protected]>
> Hi everyone,
> 
> I'm having a problem that may either lie in PostgreSQL or in perl, and
> I'm not sure which.  I originally posted this on pgsql.general, and
> only heard back that someone else has this problem too.  I'm running
> perl 5.10 on Windows 2003 Server, although I believe the version
> embedded in pgsql at the moment is still 5.8.
> 
> The basic problem is that I generate the code of a function, and then
> want to check whether this is the same code stored in the database or
> not, but diff shows "differences" where there aren't any (or shouldn't
> be any, since nothing in the database has changed), and worse, perl's
> 'eq' and 'ne' operators agree with diff that the strings are
> different.  But at least visually the two texts being compared are
> identical, and if I copy and paste the results from Firefox into
> TextPad and then run "compare files", it says they're identical.

Run the two strings through

sub nicehex {
  my $s = $_[0];
  my $hex = unpack 'H*', $s;
  $s =~ tr/\x00-\x0A/./;
  $hex =~ s/(..)/$1 /g;

  my @hex = ($hex =~ /(.{47}) /g);
  my @s = ($s =~ /(.{16})/g);

  my $res = '';
  while (@s) {
    $res .= shift(@hex) . '   |' .shift(@s) . "\n";
  }
  return $res;
}

and compare (visualy) the results. Maybe some spaces are tabs or vice 
versa. See what are the different characters.

Space: 20
Tab: 09
CR: 0d
LF: 0a
Nonbreakable space: a0

HTH, Jenda
===== [email protected] === http://Jenda.Krynicky.cz =====
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