Checking if your code is running on 64-bit PHP

Question

Does anyone know of a way of checking within PHP if the script is running as either 32-bit or 64-bit? Currently I\'m using PHP 5.3.5.

Ideally I\'d like to write a f

Answer 1

You could write a function like this:

function is_32bit(){
  return PHP_INT_SIZE === 4;
}

Then you could use the sample code you posted:

if ( is_32bit() ) {
    do_32bit_workaround();
} else {
    do_everything_else();
}

Answer 2

I just looked around and didn't find anything too promising. There's a good chance that you can use $_SERVER['SERVER_SOFTWARE'] to tell (check out what it prints on your system), but making this portable and always accurate is probably not doable.

Answer 3

Check the PHP_INT_SIZE constant. It'll vary based on the size of the register (i.e. 32-bit vs 64-bit).

In 32-bit systems PHP_INT_SIZE should be 4, for 64-bit it should be 8.

See http://php.net/manual/language.types.integer.php for more details.

Answer 4

A short way to get the number of bits.

    strlen(decbin(~0));

How this works:

The bitwise complement operator, the tilde, ~, flips every bit.

@see http://php.net/manual/en/language.operators.bitwise.php

Using this on 0 switches on every bit for an integer.

This gives you the largest number that your PHP install can handle.

Then using decbin() will give you a string representation of this number in its binary form

@see http://php.net/manual/en/function.decbin.php

and strlen will give you the count of bits.

Here is it in a usable function

function is32Bits() {
    return strlen(decbin(~0)) == 32;
}

Answer 5

Here is an example that can be used from console

For Windows:

php -r "echo (PHP_INT_SIZE == 4 ? '32 bit' : '64 bit').PHP_EOL;" && php -i | findstr Thread

For Linux

php -r "echo (PHP_INT_SIZE == 4 ? '32 bit' : '64 bit').PHP_EOL;" && php -i | grep Thread

Output example:

64 bit
Thread Safety => disabled