sum in a texfile

devil_online

Hi, I have a text file with a number, and I want to php add 1 more.

For example I have write '2' on the text file, and php write '3'...to sum one more

How can I do that

devinemke

is the number the only thing in the text file? if so:

$num = file_get_contents('/path/to/file.txt');
echo ++$num;

devil_online

sorry, i'm not explain my issue very well

That code only displays da content of the file (it's only a number) but didn't add.

Second I want that addition directly on the text file...

How can I do that?
Thanks in advance.

TheDefender

The math doean't actually occur on the text file. You have to get the contents, do the math with PHP and write the contents back to the text file. This can be done a bit more efficiently, but I wanted you to see the process...

//Read the contents into a variable
$filename = "/path/to/file.txt";
$num = fopen($filename, "rb");
$contents = fread($num, filesize($filename));
fclose($num);

//Increment the number
$contents++;

//Write it back to the file
$changeit = fopen($filename, "w+b");
fwrite($changeit, $contents);
fclose($changeit);

devil_online

it gives an error in this line (12)

$changeit = fopen($filename, "w+b");

this is the error:
Parse error: parse error, unexpected T_VARIABLE in d:(..)\easyphp1-7\www\test\write.php on line 12

Why?

thanks

devil_online

ok..now it works
its misses ";"

//Increment the number
$contents++;

now it works 😃

TheDefender

Sorry, my typo... I edited my original post to reflect the change.

devil_online

😃 thanks..I get the idea, but can I get this in a funtion and call it when I want...or there is any idea to make it simpler 😃

Thanks

TheDefender

function updateCounter()
{
    //Read the contents into a variable 
    $filename = "/path/to/file.txt"; 
    $num = fopen($filename, "rb"); 
    $contents = fread($num, filesize($filename)); 
    fclose($num); 

//Increment the number 
$contents++; 

//Write it back to the file 
$changeit = fopen($filename, "w+b"); 
fwrite($changeit, $contents); 
fclose($changeit);
}

Usage (just call the function when you need it):

updateCounter();

laserlight

To expand on TheDefender's idea, you could write a function that is more flexible in working with different counter files, and which has better error checking, e.g.

function updateCounter($filename) {
	//read contents of file $filename into $num
	if (($num = file_get_contents($filename)) !== false) {
		$num++; //increment current count
		if (($fp = fopen($filename, "wb")) !== false) {
			//store new count
			if (fwrite($fp, $num) !== false) {
				fclose($fp);
				return $num; //new count value
			} else {
				fclose($fp);
				return false;
			}
		} else {
			return false;
		}
	} else {
		return false;
	}
}

To use it, you might do a:

if (($count = updateCount("/path/to/file.txt")) !== false) {
	echo "Current count is " . $count;
} else {
	echo "Error: could not retrieve current count";
}