[Resolved] Problem compareing strings, newline?

journy101

I have this problem where a string froma file compared to the identical string in a GET request do not match. I believe there is a newline at the end of each line in the file stopping the compare from returning true. I tryed useing php's rtrim and chop and both of which cause the php to give me a warning about timeing out.

$invite = $_GET['invite'];

if ( strlen($invite == 0) || !isset($invite) ){
print "You were not invited sorry.";
exit;
}

$file = "../private/invites.txt";  //each line of file contains a invite ID
$fp = fopen($file, "r");
$contents = fread($fp, filesize($file));
$lines = explode("\n",$contents);
$ok = 0;  // Assume not ok

for ($n = 0;$n <= sizeof($lines);$n++){  // loop through invites
echo "<br>$invite::$lines[$n]";
if ($invite == $lines[$n]){
print "<br>Yes your invite matched one in our database.";
$ok = 1;  // you were invited so lets continue
}
}

if ($ok == 0){
print "<br>Im sory but our records show your invitatin ID is invalid, Please contact me.";
} else {
print "<br>Your Invitation is ok";
}
fclose($fp);

The output would be:

345::642
345::345
345::326
345::
Im sory but our records show your invitatin ID is invalid, Please contact me.

Ass you can see 345::345 are the same value, but I think the newline is stoping it. Trying rtrim caused a long time for the page to load and when it finaly loads it gives me a warning about execution takeing a long time on line 24, the line that my rtrim was on.

Mordecai

Try using $line[$n] = str_replace("\n","",$lines[$n]);
It just replaces all newlines with an empty string.

matt_4013

I'm pretty sure it wouldn't be a newline character being the problem, because your explode would be stripping them.

Try doing a var_dump on each of your variables, ie

echo "<br>".var_dump($invite)."::".var_dump($lines[$n]);

Just to make sure that there's actually what you'd expect in there.

journy101

Heres the update, first I tryed str_replace, and that just issued a fatal error on maximum execution of 30 seconds. I then tryed the var_dump, and

string(3) "345" string(4) "642 "
::string(3) "345" string(4) "345 "
Yes your invite matched one in our database.string(3) "345" string(3) "326"
::string(3) "345" NULL
::string(3) "345" NULL // I get dozens of these continued down

Seeing that ::string(3) "345" NULL was repeaded a couple of dozen times I thought something must be wrong with the for loop. So I changed the condition <= to just a lessthen because when I printed the value of $n I found that although sizeof($lines) was 3 the value of $n was going 0 1 2 3

This fixed the problem of the repeating ::string(3) "345" NULL and made execution time cut down dramaticaly. But still the statement wasnt matching and seeing the var dump gave the space at the end, and str_replace was not geting rid of it I tryed rtrim again. This time rtrim worked and execution time was normal.

My conclusion it was a dual problem of one my for loop conditional statement and there was not a new line but a leading white space instead, so rtrim came to my resuce.

thank you both, useing both of your sugestions I was able to narow down my bug.

for ($n = 0; $n < sizeof($lines); $n++){  // loop through invites
$lines[$n] = rtrim($lines[$n]); 
if ($invite == $lines[$n]){
print "<br>Yes your invite matched one in our database.";
$ok = 1;  // you were invited so lets continue
}
}

matt_4013

How about giving this a go:

$invite = $_GET['invite'];

if ( strlen($invite == 0) || !isset($invite) ){

print "You were not invited sorry.";
exit;
}

$file = "../private/invites.txt";  //each line of file contains a invite ID
$fp = fopen($file, "r");

// Set the 2 variables, $i for a line counter and $lines to hold the lines
$i = 0;
$lines = array();

/* Loop through each line of the file, until EOF. We use fgets here because it will get 
everything until either 1024 bytes, or the newline character is matched */

while(!feof($fp)) {

$lines[$i] = fgets($fp, 1024);
}

// Close the file here, no need to leave it open if you aren't using it
fclose($fp);

$ok = 0;  // Assume not ok

for ($n = 0;$n <= sizeof($lines);$n++){  // loop through invites

// Strip all of the newline characters
$lines[$n] = str_replace("\n", "", $lines[$n]);

echo "<br>$invite::$lines[$n]";

if ($invite == $lines[$n]){

	print "<br>Yes your invite matched one in our database.";
	$ok = 1;  // you were invited so lets continue
}
}

if ($ok == 0){

print "<br>Im sory but our records show your invitatin ID is invalid, Please contact me.";
} else {

print "<br>Your Invitation is ok";
}

suntra

There is an error in the code of matt_4013...

while(!feof($fp)) {

$lines[$i] = fgets($fp, 1024);
}

$i doesn't get incremented... Should be :

while(!feof($fp)) {

$lines[$i] = fgets($fp, 1024);
$i++;
}

But why don't you just use file() ? It opens a file and put each line in an array... and if you use trim() when you read each line, it will remove unuseful \n (http://www.php.net/manual/en/function.trim.php).

journy101

Thank you suntra, and all who helped. I got my code working now with the change in my for condition, and useing rtrim, but will now try with your sugested trim and file() I read alot of the php.net and found the comments are very helpfull. and often I get good examples.

thanks everyone.