Check if a file was included or loaded

Question

Is there any elegant way to check if a file was included by using include/include_once/require/require_once or if the pag

Answer 1

get_included_files() return array where 0 index mean first "included" file. Because direct run mean "include" in this terms, you can simple check first index for equality for __FILE__:

if(get_included_files()[0] == __FILE__){
    do_stuff();
}

This can not work on PHP 4, because PHP 4 not add run file in this array.