Use variable in the function, that declare in the file

[mikerh9]

I wrote small script that send an email to me when the IP was modified on my computer.
The script works. I just have small PHP question:

I declare $filename at the beginning of the script. So $filename I suppose should be available from everywhere.
In these function I use this variable in order to open the file:write_ip_to_the_file & get_old_ip.

However, when I use the variable from the top I get such message:
<b>Warning</b>: fopen("", "r") - Operation now in progress in...
But When I declare the variable locally in each function I don't get the message. Any ideas why?
How variable should be declare, in order to be availabe from functions?

<?php
//Curl request
$filename = "existingIP.dat";
$ch = curl_init("ip.php");
ob_start();
curl_exec($ch);
curl_close($ch);
$retrievedhtml = ob_get_contents();
ob_end_clean();

//String parsing and removing unnecessary data
$withnotags = strip_tags($retrievedhtml);
//$length_of_string = strlen($withnotags);
$last_occurance = substr($withnotags,0,15);
$previous_ip = get_old_ip();

if($last_occurance != $previous_ip) {
echo 'Changed IP';
send_email_with_ip($last_occurance);
write_ip_to_the_file($last_occurance);
}

//#########################################################
//SEND_EMAIl_WITH_IP: returns none
//#########################################################
function send_email_with_ip($last_occurance) {
//Creating Send Email Data
$to = 'root@localhost';
$today = date("F j, Y, g:i a");
$new_ip = $last_occurance."\t".$today;
$Data = $last_occurance."\t".$today;

//Creating header for Email
$headers = "From:".$to."\r\n";
$headers .= "MIME-Version: 1.0\r\n";
$headers .= "Content-Type: text/html; charset=iso-8859-1\r\n";
mail($to, $new_ip, $Data, $headers);
}

//#########################################################
//WRITE_IP_TO_THE_FILE: returns none
//#########################################################
function write_ip_to_the_file($last_occurance) {
$filename = "existingIP.dat";
if(!$handle = fopen($filename, 'w')){
print "Cannot open file ($filename)";
exit;
}
if(is_writable($filename)) {

if(!fwrite($handle, $last_occurance)){
print "Cannot write to file ($filename)";
exit;
}
}
fclose($handle); //Close the file
}

//#########################################################
//GET_OLD_IP: returns old_ip
//#########################################################
function get_old_ip() {
$filename = "existingIP.dat";

//Open the file
if(!$handle = fopen($filename, "r")) {
print "Cannot open file ($filename)";
exit;
}
if(is_readable($filename)) {
if(!$old_ip = fread($handle,15)) {
print "Cannot read from the ($filename)";
}
}

fclose($handle);//Close the file
return $old_ip;
}
?>

[keith73]

$filename is out of scope for the function.
inside the function, if you want to use variables declared outside the function, you need to either pass the variable to the function or declare it as global inside the function.

example:

$filename = "foo.txt";

//declare as global inside function
function openFoo(){
    global $filename;
    fopen($filename,"r");
}//end function

• keith