Solved

Extracting web links from string

Posted on 2004-04-24
8
329 Views
Last Modified: 2010-04-05
Hello,

How can I extract web links from string, for example I have string with web links and other text and I need only those web links that match special code or text.
0
Comment
Question by:H-styler
8 Comments
 
LVL 17

Expert Comment

by:mokule
ID: 10907060

I advise regular expressions.

Freeware for Delphi
http://regexpstudio.com/TRegExpr/TRegExpr.html
0
 
LVL 17

Expert Comment

by:mokule
ID: 10907068

This is an example of regular expression from TRegExpr test program for extracting URL from text.

(?i)                          # we need caseInsensitive mode
(FTP|HTTP)://                 # protocol
([_a-z\d\-]+(\.[_a-z\d\-]+)+) # TCP addr
((/[ _a-z\d\-\\\.]+)+)*       # unix path
0
 
LVL 3

Accepted Solution

by:
Kunfufaresi earned 50 total points
ID: 10907298
Hello, not as fancy as regex but you could use this code

s:String;
i :integer;

begin
 s := texttoparse;
 repeat
  i := pos('http://',s);
  if i>0 then
  begin
   delete(s,1,i-1);
   i := pos(' ');
   if i=0 then i := length(s)+1;
   listbox1.items.add(copy(s,1,i-1)); // so the url is = copy(s,1,i-1)
   delete(s,1,i);
  end;
 until i=0;
end;

well this would work if your urls doesnt contain spaces which they shouldnt as spaces are encoded already.

Kunfu Faresi
0
Courses: Start Training Online With Pros, Today

Brush up on the basics or master the advanced techniques required to earn essential industry certifications, with Courses. Enroll in a course and start learning today. Training topics range from Android App Dev to the Xen Virtualization Platform.

 
LVL 17

Expert Comment

by:mokule
ID: 10907314
I advise regexpr because he wrote
"I need only those web links that match special code or text."
0
 
LVL 3

Expert Comment

by:Kunfufaresi
ID: 10907605
Yes you are right, regexp is much more advanced, but i've used it some times and still have not gotten all the hang of it.
0
 

Author Comment

by:H-styler
ID: 10908088
Kunfufaresi with your code I can`t extract links from this type of string:

<table border=0 cellpadding=0 cellspacing=0 bgcolor=ffffff><tr><td><a href="http://www.bythebeachemails.com/scripts/runner.php?PA=116" target=_ptc onclick="javascript:reloadpage(30)"><img src=http://www.bythebeachemails.com/scripts/runner.php?REDIRECT=http%3A%2F%2Fmpam2.free.fr%2Fcash%2Fbann_cash2.gif alt="Great PTR/PTC sites" width=468 height=60 border=0></a></td></tr></table>The ad above is worth 50 cent(s)<br><br><br><br><br><b>1</b><br> <br>

And I only need to extract those links witch match for example this code: "scripts/runner.php?PA="
0
 
LVL 3

Expert Comment

by:Kunfufaresi
ID: 10908442
Hello,

well if you did a

if pos('scripts/runner.php?PA=',copy(s,1,i-1))>0 then listbox1.items.add(copy(s,1,i-1));

also you should in this case look for pos('"',s) instead of pos(' ',s) as " terminates the url not space.
0
 
LVL 4

Expert Comment

by:ceoworks
ID: 10932036
As mokule said i suggest you to use regular expressions. Here is some usefull stuff http://www.regular-expressions.info/ and if you will search for regular expressions in www.torry.ru, you may found some freeware components.

Regards,
0

Featured Post

Live: Real-Time Solutions, Start Here

Receive instant 1:1 support from technology experts, using our real-time conversation and whiteboard interface. Your first 5 minutes are always free.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
Introduction Raise your hands if you were as upset with FireMonkey as I was when I discovered that there was no TListview.  I use TListView in almost all of my applications I've written, and I was not going to compromise by resorting to TStringGrid…
This Micro Tutorial will give you a basic overview how to record your screen with Microsoft Expression Encoder. This program is still free and open for the public to download. This will be demonstrated using Microsoft Expression Encoder 4.
Finds all prime numbers in a range requested and places them in a public primes() array. I've demostrated a template size of 30 (2 * 3 * 5) but larger templates can be built such 210  (2 * 3 * 5 * 7) or 2310  (2 * 3 * 5 * 7 * 11). The larger templa…

786 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question