Splitting up a large text document into multiple smaller text files - php

Question

I am developing a text collection engine using fwrite() to write text but I want to put a file size cap of 1.5 mb on the writing process so if the file is larger that 1.5mb it will start writing a new file from where it left off and so on until it writes the contents of the source file into multiple files. I have Google-searched but many of the tutorials and examples are too complex for me because I am a novice programmer. The code below is inside a for loop which fetches the text ($RemoveTwo). It does not work as I need. Any help would be appreciated.
switch ($FileSizeCounter) {
case ($FileSizeCounter> 1500000):
$myFile2 = 'C:\TextCollector/'.'FilenameA'.'.txt';
$fh2 = fopen($myFile2, 'a') or die("can't open file");
fwrite($fh2, $RemoveTwo);
fclose($fh2);
break;
case ($FileSizeCounter> 3000000):
$myFile3 = 'C:\TextCollector/'.'FilenameB'.'.txt';
$fh3 = fopen($myFile3, 'a') or die("can't open file");
fwrite($fh3, $RemoveTwo);
fclose($fh3);
break;
default:
echo "continue and continue until it stops by the user";
}

Answer 1

Try doing something like this. You need to read from a source then write piece by piece all the while checking for end of file from the source. When you compare the max and buffer values, if they are true, then close the current file and open a new one with an auto-incremented numeric:
/*
** #param $filename [string] This is the source
** #param $toFile [string] This is the base name for the destination file & path
** #param $chunk [num] This is the max file size based on MB so 1.5 is 1.5MB
*/
function breakDownFile($filename,$toFile,$chunk = 1)
{
// Take the MB value and convert it into KB
$chunk = ($chunk*1024);
// Get the file size of the source, divide by kb
$length = filesize($filename)/1024;
// Put a max in bits
$max = $chunk*1000;
// Start value for naming the files incrementally
$i = 1;
// Open *for reading* the source file
$r = fopen($filename,'r');
// Create a new file for writing, use the increment value
$w = fopen($toFile.$i.'.txt','w');
// Loop through the file as long as the file is readable
while(!feof($r)) {
// Read file but only to the max file size value set
$buffer = fread($r, $max);
// Write to disk using buffer as a guide
fwrite($w, $buffer);
// Check the bit size of the buffer to see if it's
// same or larger than limit
if(strlen($buffer) >= $max) {
// Close the file
fclose($w);
// Add 1 to our $i file
$i++;
// Start a new file with the new name
$w = fopen($toFile.$i.'.txt','w');
}
}
// When done the loop, close the writeable file
fclose($w);
// When done loop close readable
fclose($r);
}
To use:
breakDownFile(__DIR__.'/test.txt',__DIR__.'/tofile',1.5);