Retrieving the string between a pattern

sgs

I need to extract a string between a particular pattern.
e.g. All the characters appearing between the pattern starting with <%sgs; and ending with 'sgs%>

I am using ereg function but not able to figure out the way i will format my pattern. Can someone help me ???

Weedpacket

Without seeing your code, I can only speculate; but a general principle in problems of this nature is to realise that the ereg_* functions have piss-poor syntax that won't do the job you want without serious masochism on your part.

So use the preg_match() function instead. Works the same way as ereg, but with a more sophisticated syntax, in which the expression you want becomes

"/<%sgs((?:(?!%sgs>).)*)%sgs>/"

sgs

tried the same , not working 🙁

any more suggestions ??

Weedpacket

Spot the obvious typo?

"/<%sgs((?:(?!sgs%>).)*)sgs%>/"

Works for me.

bernouli

how bout this

<?php
$string = "blah blah <sgs; the string to be extracted ;sgs> blah blah blah"; 
eregi ( "<sgs;(.*);sgs>", $string ,$regs) ;
echo $regs[1];
?>

Weedpacket

Originally posted by bernouli
how bout this

How 'bout this:

php

$string = "blah blah <sgs; the string to be extracted ;sgs> blah blah blah <sgs; another string to be extracted ;sgs> blah blah blah"; 

eregi ( "<sgs;(.*);sgs>", $string ,$regs) ;

echo $regs[1];

sgs

I had already tried both of these :

if(eregi ( "<%sgs;(.*);sgs%>", $string ,$regs) ) echo "match found";
else echo "match not found";

did not work. Simply displays 'match not found'

if(eregi ( "/<%sgs((?🙁?!sgs%>).)*)sgs%>/", $string ,$regs)) echo "match found";
else echo "match not found";

also did not work. Shows a warning as "Invalid preceding regular expression on the line --" and displays 'match not found'

Any more suggestions r welcome.

!!!!!

bernouli

why did not work?
which problem did you get?

sgs

Originally posted by bernouli
why did not work?
which problem did you get?

Kindly refer the above modified posting for the prob I got.

bernouli

and which strings are you searching for?

sgs

Let me give the string from which I am searching for 'the_string_to_be_extracted'

$string = "blah blah <%sgs; the_string_to_be_extracted ;sgs%> blah blah blah";

bernouli

<?php

$string = "blah blah <%sgs; the_string_to_be_extracted ;sgs%> blah blah blah";

if(eregi ( "<%sgs;(.*);sgs%>", $string ,$regs) ) echo "found"; else echo "not found";
?>
//result: found

Weedpacket

Originally posted by sgs
I had already tried both of these :

if(eregi ( "/<%sgs((?🙁?!sgs%>).)*)sgs%>/", $string ,$regs)) echo "match found";
else echo "match not found";

also did not work. Shows a warning as "Invalid preceding regular expression on the line --" and displays 'match not found'
[/B]

Repost of part of an earlier post:

....A general principle in problems of this nature is to realise that the ereg_* functions have piss-poor syntax that won't do the job you want without serious masochism on your part.

So use the preg_match() function instead. Works the same way as ereg, but with a more sophisticated syntax, in which the expression you want becomes
"/<%sgs((?:(?!sgs%>).)*)sgs%>/"

Really, I don't know why I bother, sometimes...

sgs

Thanks for bothering urself this time but as I have mentiioned even before I have tried using both eregi and preg_match but gives me the same result as :

"match not found."

(with preg_match it is not giving me the warning though )

Any more suggestions ???

bernouli

its really interesting
by me its just showed "match found" when i use the code and the string above

can you give us exactly what you are typing (the codes and the string) ?

sgs

Yes , Indeed the prob is interesting !!!

Let me give u an overview of my code(if not the entire code) I am retrieving a huge string from the database. This string basically has the html page source (all html tags) within which the pattern <%sgs; ;sgs%> is existing. The pattern has some html code (like a <table> <tr><td> etc) which needs to be modified and then replaced when certain condition are met. It's for the same reason , I need to extract it. This is where I faced the prob as we have been discussing above.

Well , I did some more R&D on the same , and feel that this has something to do with the size of string. I reduced some of the content from the html page source in a step by step way and found that at a particular point it works !! Now so as what is the upper limit for the size of string , I am not able to figure out.

Is my feeling right ? Is it possible that the size of the string can affect the pattern matching ? If so , any idea what is the upper limit for the size of string ?

Awaiting ur response. Thanks for ur kind attention.

Regards ,
SGS

bernouli

what about when you use htmlspecialchars() the string you retrieve from the database before you search the string

$string= htmlspecialchars($string);
then you search it with the codes

sgs

tried using htmlspecialchars , but no result.

Just thought I should mention , I am using addslashes before adding the string into the db , and using stripslashes at the time of retrieving it from db. I tried using htmlspecialchars both before and after using stripslashes , but still did not work

😕

Any more suggestions ??