getenv

(PHP3 , PHP4 )

getenv -- Get the value of an environment variable

Description

string getenv (string varname)

Returns the value of the environment variable varname, or false on an error.


$ip = getenv ("REMOTE_ADDR"); // get the ip number of the user 
      

You can see a list of all the environmental variables by using phpinfo(). You can find out what many of them mean by taking a look at the CGI specification, specifically the page on environmental variables.