Required PHP Coding for How to create text file in client machine(Local machine):

How to create a text file in client machine(Local machine)?

What do you mean by client machine?

however, to create a text file:

$file = fopen("myTextFile.txt","w");
fwrite($file,"This is where the contents of the text file goes");
fclose($file);

for more info see link below:
http://www.php.net/manual/en/function.fopen.php