[The Real Slim Shady]

@404#, firstly thank you to All your Post on my third, your help full about me, but I have one question: developers of PHP why Add those Functions to php language?
sorry for my bad English

Because they are useful functions within the language that many people can use. However when PHP was designed it was not for a multi-user environment... and in a multi-user environment many of those functions are a high security risk. That is why the ability to disable them was added... and it's why every host I know who offers shared (multi-user) hosting disables them. the only time you get these functions are when you have private hosting such as VPS, colocated, or dedicated hosting services.