pg_client_encoding() returns the client encoding as the string. The returned string should be either : SQL_ASCII, EUC_JP, EUC_CN, EUC_KR, EUC_TW, UNICODE, MULE_INTERNAL, LATINX (X=1...9), KOI8, WIN, ALT, SJIS, BIG5, WIN1250.
Note: This function requires PHP-4.0.3 or higher and PostgreSQL-7.0 or higher. If libpq is compiled without multibyte encoding support, pg_set_client_encoding() always return "SQL_ASCII". Supported encoding depends on PostgreSQL version. Refer to PostgreSQL manual for details to enable multibyte support and encoding supported.
The function used to be called pg_clientencoding().