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Using GET in a loop: msg#00031

lang.perl.modules.lwp

Subject: Using GET in a loop

Hi,

I am experiencing problems when working with GET in a loop.

I want to retrieve information from a number of pages that all have the same
structure. Thus, I would like to use a retrieve them via GET and process their
information in a loop. However, GET seems to store the information in a hidden
variable and appends it. Instead of replacing the content of my "temporary"
variable the content of the new website is appended to the content of all
previously retrieved ones. Thus, my information processing (getting various
information from the "temporary" content variable and assigning it to other
variables) always yields the same results, the one from the first website
retrieved. Because I rely on the structure of the website to identify the
necessary bits and pieces of information, I need the content variable to be
replaced everytime.

I already tried global and local variables. Furthermore, I "empty" the content
variable every time prior to retrieving a new site. None of this works. I
thought about having one content variable per site (e.g., $content1, $content2,
...), but this isn't very efficient, is not very much in the spirit of
variables and I wouldn't know how to automatically generate a new variable for
each round of the loop (if that is possible) anyway.

Here is the (abbreviated) code:

<code>
use LWP::Simple;
foreach $ID (@ID) {
$content=" ";
$url="http:://...docid=$ID";
$content=get($url);
# subsequently I extract information from the string
# $content, which only serves as a contemporary storage
Open FILE, ">> C:/perl/output.txt"
Print FILE $content;
# actually it's all the other variables whose values I
# want to save
}


Any help would be greatly appreciated!
Best,

Andreas
__________________________

Andreas Warntjen
LSE Butler's Wharf
11, Gainsford Street
London , SE1 2NE
United Kingdom

http://personal.lse.ac.uk/warntjen
Phone: +44 (0)870 036 6666, ext. 2985
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