Re: Extracting from a File

When you are extracting from something that uses fixed length columns, sometimes unpack is the way to go. Using the example you have given, you can get the column data with something like this:

my @cols = unpack ("A4 A4 A4 A6 A4 A5", $_);

This is probably a lot easier than working with individual characters, which is what you get when using split (//).

As for how you choose to organize your data, that's up to you.

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Re: Re: Extracting from a File by physi (Friar) on May 15, 2002 at 17:32 UTC
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 `----------------------------------- --the good, the bad and the physi-- -----------------------------------` [download]	[reply] [d/l]
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})); } }` [download] 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.	[reply] [d/l]
Re: Re^3: Extracting from a File by physi (Friar) on May 15, 2002 at 18:54 UTC
Thanks, that idea saves me abot 70% time :-) ++ `----------------------------------- --the good, the bad and the physi-- -----------------------------------` [download]	[reply] [d/l]