Re: How to read just part of a url's content

You mean just get part of the file located with the URL?

There is almost certainly a way to do it, since wget (et al) can be instructed to continue.

Personally, I can't find a single relevant option in LWP, LWP::UserAgent, HTTP::Request, HTTP::Headers, and more.

I'm very curious to see how how you would get a selected portion of a file with LWP. Someone will know.

UPDATE #1: Further investigation has revealed that you can set a "range" header with
$request_object->header( $field => $value ); but I haven't yet worked out the particulars of the header.

use strict;
use LWP::UserAgent;
use HTTP::Request;

my $ua   = LWP::UserAgent->new();
my $req1 = HTTP::Request->new(GET => $your_URL);
   $req1->header( Range => 'bytes=0-499' ); # bytes 0 through 499

my $req2 = HTTP::Request->new(GET => $your_URL);
   $req2->header( Range => 'bytes=500-' ); # bytes 500 onward

my $res1 = $ua->request( $req1 => "file1.html" );
my $res2 = $ua->request( $req2 => "file2.html" );


# A byte range operation MAY specify a single range of bytes, or a set
+ of ranges within a 
# 
#       ranges-specifier = byte-ranges-specifier
#       byte-ranges-specifier = bytes-unit "=" byte-range-set
#       byte-range-set  = 1#( byte-range-spec | suffix-byte-range-spec
+ )
#       byte-range-spec = first-byte-pos "-" [last-byte-pos]
#       first-byte-pos  = 1*DIGIT
#       last-byte-pos   = 1*DIGIT
[download]

-Paul

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Re^2: How to read just part of a url's content by ikegami (Patriarch) on May 29, 2007 at 19:56 UTC
You mean just get part of the file located with the URL? No, "file" is a less accurate accurate word. The content identified by a URI is not necessarily a file.	[reply]
Re^3: How to read just part of a url's content by jettero (Monsignor) on May 30, 2007 at 03:25 UTC
That's a semantic argument. Is a file a space on a hard drive? Is it a stream of bytes? A sector on a tape? There's an application where I work that describes a file as 100 variably sized blocks. My point was that the URL just describes the location of something. You already have it. -Paul	[reply]