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Checking if your code is running on 64-bit PHP

Does anyone know of a way of checking within PHP if the script is running as 开发者_Go百科either 32-bit or 64-bit? Currently I'm using PHP 5.3.5.

Ideally I'd like to write a function so my code can look like this:

if( is_32bit() === true ) {
    do_32bit_workaround();
}
do_everything_else();

Anyone have any thoughts?


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.


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();
}


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


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;
}
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