(PHP4 >= 4.0b4)
readline_completion_function -- Registers a completion function
Description
boolean 
       readline_completion_function
       (string line)
     This function registers a completion function.  You must supply
     the name of an existing function which accepts a partial command
     line and returns an array of possible matches.  This is the same
     kind of functionality you'd get if you hit your tab key while
     using Bash.