(PHP 7 >= 7.1.0, PHP 8)
sapi_windows_cp_conv — Convert string from one codepage to another
$in_codepage, int|string $out_codepage, string $subject): ?stringConvert string from one codepage to another.
in_codepage
      The codepage of the subject string.
      Either the codepage name or identifier.
     
out_codepage
      The codepage to convert the subject string to.
      Either the codepage name or identifier.
     
subjectThe string to convert.
   The subject string converted to
   out_codepage, or null on failure.
  
   This function issues E_WARNING level errors, if invalid codepages are given,
   or if the subject is not valid for in_codepage.