in reply to Re: Extracting from a File
in thread Break List into Pieces (was: other ways ?)

Thanks, but I have to work with individual chars, cause the problem is, that some 'tags' are like blocks. For example: starting in line 5, column 12, length 10 and continue on line 6, column 12, length 10 ,... and so on. So there is no chance to do it by an unpack :-(
cheers 
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Re^3: Extracting from a File
by tadman (Prior) on May 15, 2002 at 18:02 UTC
    I wouldn't dismiss unpack so soon. If you can develop a specification like the one you just said there, then you can use it. As an alternative, if things really are quite wacky, why not specify the position of elements in a hash and use that in conjunction with substr? 
    my @frags = (
     { line => 5, column => 12, length => 10, name => 'foo' },
     { line => 6, column => 12, length => 10, name => 'foo' },
);

# ...
my %var;

# @chunks is an array of arrays, where each contains a
# block of the file.
foreach my $chunk (@chunks)
{
     foreach my $frag (@frags)
     {
          push(@{$var{$frag->{name}}}, 
            substr($chunk->[$frag->{line}],
                   $frag->{column},
                   $frag->{length}));
     }
}

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    It will probably be a lot faster to use substr or unpack than to glue individual characters together, especially when you are pulling them out of a complex data structure and not just a string.
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[d/l]
      Thanks, that idea saves me abot 70% time :-)
      ++ 
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