These
are not actual extensions. They are part of the PHP core and cannot be
left out of a PHP binary with compilation options.
Reference V, Array Functions
Reference XII, Class/Object Functions
Reference XXII, Date and Time Functions
Reference XXIX, Directory Functions
Reference XXXII, Error Handling and Logging Functions
Reference CXVII, Program Execution Functions
Reference XXXVIII, Filesystem Functions
Reference XLIV, Function Handling Functions
Reference XLVIII, HTTP Functions
Reference CXI, PHP Options&Information
Reference LXVII, Mail Functions
Reference LXIX, Mathematical Functions
Reference LXXVIII, Miscellaneous Functions
Reference XC, Network Functions
Reference CIII, Output Control Functions
Reference CXIII, Regular Expression Functions (POSIX Extended)
Reference CXXXIV, Session Handling Functions
Reference CXLIV, Stream Functions
Reference CXLV, String Functions
Reference CL, Tokenizer Functions
Reference CLII, URL Functions
Reference CLIII, Variable Handling Functions