how to trim a string

[DARTHTAMPON]

ok i have many strings that look something like this

/grid/thegrid.php?cords=0,0,n,0,0,w&pageflag=grid


I was just looking to figure out how to eliminate everything but the 0,0,n,0,0,w from the string.

I was looking at the trim() fuction but it seemed not to do what I wanted it to or I just didnt understand the documentation.

the 0,0,n,0,0,w value will change but will always be in a number comma number comma letter comma number comma number comma letter format.


any ideas?

I also have an issue with sending variable via get.

if i have
"/findbase/index.php?pageflag=fortlvl&fort=2" and need to send it through a form using the get method how do i keep the browser from getting confused and thinking that "pageflag=fortlvl" is part of a variable but not a variable itself?

[bokeh]

Maybe the following will give you a couple of ideas:<?php

// here's your string
$string = '/grid/thegrid.php?cords=0,0,n,0,0,w&pageflag=grid';

// Make it url safe for use in form with get method
// pretend it is coming from a form
$_GET['safe_string'] = urlencode($string);

// Later, in step two, after form submission extact 'cords'
preg_match('¥cords=(.*?)&¥i', urldecode($_GET['safe_string']), $matches);
$cords = (isset($matches['1'])) ? $matches['1'] : FALSE;

// output
print $cords;

?>

[insane]

why can't you just use $cords = $_GET['cords'];?

-Insane

[chazzy]

darthtampon:

me thinks you are not clear on how the get, post arrays function and in general how HTML forms process. you can use a get. to get the information from it (same with post) you need to use the get and post arrays. they are variables. you can't say that "pageflag=fortlvl" is not a variable, that's how its designed to work. if all the requests on this page include pageflag=fortlvl then maybe you don't need to include it?

[bokeh]

why can't you just use $cords = $_GET['cords'];?

-InsaneBecause 'cords' is just part of a string. Example:

<input type="text" name="string" value="/grid/thegrid.php?cords=0,0,n,0,0,w&pageflag=grid">

As you can see it is not a variable in its own right its just part of a string. This is why he needs urlencode();. If you careful read the last sentance of the post this will become obvious.

[bokeh]

you can't say that "pageflag=fortlvl" is not a variableOf course you can if those characters are just part of a string! You are just assuming that because those characters look like a query string they are part of one. What is happening is he is trying to send that whole string as a value; it has nothing to do with variables.

[chazzy]

bokeh:

he would get the same result if he did:
if(isset($_GET['cords'])){
$string = "cords=".$_GET['cords'];
}
elseif{
//check for others..
}
is there some reference to this type of notation in the php manual, because this seems like an insecure way of handling requests imho.

[bokeh]

This is a missunderstanding. That is not a request or a variable. Example:
$string = "What time is dinner? Any time after six is good for me."; That string also contains a question mark but it has nothing to do with passing a request. The same as also the case with this post, it is just a string. That is why he is having troulbe passing it by the get method; because it looks like a query string.

Also I don't understand the point you make about a security issue since nothing is being executed. Could you explain?

[bokeh]

Chazzy, I have just thought of a valid example. I have a web page:

http://costablancatranslations.com?language=english

I want to pass that page to the validator at w3.org

http://validator.w3.org/check

The whole thing looks like this:

http://validator.w3.org/check?uri=http://costablancatranslations.com?language=english

Now look at that. We now have a second query string inside the first query string but the second query string is merely a value (and not a request) so it should be encoded with urlencode(). End result: http://validator.w3.org/check?uri=http%3A%2F%2Fcostablancatranslations.com%2F%3Flanguage%3Denglish

[chazzy]

bokeh:

I understand his issue now. Sorry about that.

[DARTHTAMPON]

// Later, in step two, after form submission extact 'cords'
preg_match('¥cords=(.*?)&¥i', urldecode($_GET['safe_string']), $matches);
$cords = (isset($matches['1'])) ? $matches['1'] : FALSE;


Could you please further explain thses lines.

preg_match( #used to find a match using regexp's
'¥ # what does the ¥ stand for? What does it do
cords=(.*?) # does this find every character between "cords=" and ?
# What if the string is at the end of the url and not in the middle?
# Well this not confuse php and throw an error or execute a different path
&¥i', # Again with the ¥ and what exactly does "&¥i'," do
# I assume the i is to ignore case but am not familyer with the rest.
urldecode($_GET['safe_string']),
# Decodes the encoded url
$matches); # the return variable. What are the possable otputs of this function?

$cords = # set variable
(isset($matches['1']))
# I thought isset was a cookie thing. Does this just check
# to see if the array has a value?
? # no idea what this does
$matches['1'] : FALSE;
# not sure what this last line does eather.

any clearification would be greatly appreciated.

tia

[NogDog]

Another way to skin the cat:

<?php
$test = "/grid/thegrid.php?cords=0,0,n,0,0,w&pageflag=grid";
$url = array_pop(explode("?", $test));
parse_str($url, $values);
echo "<p>Coordinates = {$values['cords']}</p>\n";
?>

[bokeh]

Another way to skin the catI like that better!

[SpectreReturns]

I would use parseurl() which would return the query string, which you could then parse again as a query string, and then could work with it from there.