Problems with receiving variables in an if clause

[8701]

Hi

I have a lil´ problem with a function i wrote. It´s not important what this function actually does. That part works. The problem ist the $desclngth variable. It´s not available inside the if clause. I tried to declare it as a global variable but that also seems to doesn´t work. Oh i forgot. There is also another lil problem i can´t work around. I don´t receive $$descriptor outside of the function. I know this must be a noobie-prob but i can´t find a clue. Any help would be great. So here´s the code:

function getinfo($descriptor, $datalngth)
	{
	$descstart = 0;
	$desclngth = strlen($descriptor);
	global $i, $filetxt;
	if (substr($filetxt[$i], $descstart, $desclngth)==$descriptor)
			{
			echo "Reached";
			global $datalength, $desclngth, $filetxt;
			$datastart = $desclngth + 1;
			global $$descriptor;
			echo $$descriptor[$i] = substr($filetxt[$i],$datastart,$datalngth);
			}
	else
		{
		echo "Not reached";
		}
	}

Benjamin

[laserlight]

Is the $desclngth variable declared outside the function?

Same for the variable accessed by the variable variable $$descriptor.

What does the function do?
Granted, it may seem to work, but if ppl know what you are trying to do, they might be able to suggest better ways of doing it.

Also, there's no need to declare $filetxt global a second time.
I would advise declaring all the globals at the start to avoid confusion.

[8701]

The $desclngth variable is not declared outside of the function. Could this be the whole problem?

Ok what this function does is the following. It´part of a script that opens a file and reads the content through til it finds the given $descriptor. In this special case, the script should find the following string inside of the given file: User_Name=rothb
If this string is found, the script should substr the User_Name= thing and only leave the information like rothb and set it as a variable named like the $descriptor. In this case the variable should have the name $User_Name.

When i call the function it looks like:

getinfo(User_Name, 10);

The function determines the length of the given $descriptor for the following if clause. When it finds the above mentioned string, it enters the if clause (it does i already tested it). And then it should define $datastart (The point where the information data starts) by increasing $desclngth by 1 cause of the =.
$datalngth defines the end of the information data.
Hope this is not too confusing.

Benjamin

[8701]

Oh i forgot. $filetxt is an array containing the data from the given information file.

Benjamin

[laserlight]

oic
May I suggest a slight change then?
getinfo() accepts the descriptor, the number of characters following the descriptor that should be read, as well as the string that is to be parsed.
It returns the characters following the descriptor, if any.

function getinfo($descriptor, $readlen, $data)
{
	//find the descriptor
	$descpos = strpos($data, $descriptor);
	//change the position to the end of the descriptor
	//I think that this takes into account the = sign (not sure though)
	$descpos += strlen($descriptor);
	//now we get the info we want
	return substr($data, $descpos, $readlen);
}

Now, once you have the info, you can use it

i.e.

$User_Name = getinfo("User_Name", 10, $string);

[laserlight]

okay, then I presume $filetext was taken using file()?
I suspected that, since the info would probably be on a line like some config files.

in that case

function getinfo($descriptor, $readlen, $data_array)
{
	//identify which line (i.e. array element) the descriptor is on
	$datasize = count($data_array);
	$index = -1;
	for ($i = 0; $i < $datasize; $i++)
	{
		if (strstr($data_array[$i]))
		{
			$index = $i;
			break;
		}
	}
	if ($index < 0)
	{
		//couldnt find the descriptor
		return;
	}
	else
	{
		//find the descriptor
		$descpos = strpos($data_array[$i], $descriptor);
		//change the position to the end of the descriptor
		//Re: may have = sign problem, must test!
		$descpos += strlen($descriptor);
		//now we get the info we want
		return substr($data_array[$i], $descpos, $readlen);
	}
}

[laserlight]

I tested with this one, it correctly retrieved from a file:

User_id=10;
Username=Rasmus Lerdorf
Password=php/fi

<?php
function getinfo($descriptor, $readlen, $data_array)
{
	$datasize = count($data_array);
	for ($i = 0; $i < $datasize; $i++)
	{
		if (!($info = strstr($data_array[$i], $descriptor)))
		{
			continue;
		}
		else
		{
			return substr($info, strlen($descriptor) + 1, $readlen); 
		}
	}
	return "";
}

$filetxt = file("testfile.txt");
$info = getinfo("Username", 20, $filetxt);
echo "Username: " . $info;
?>

[8701]

It works great. Mine works too, now. It seems, that i made a mistake while calling the function. Anyway, thank you for your great help. 🙂

Benjamin