_php_iconv_substr  207 ext/iconv/iconv.c static php_iconv_err_t _php_iconv_substr(smart_str *pretval, const char *str, size_t nbytes, zend_long offset, zend_long len, const char *enc);
_php_iconv_substr 2108 ext/iconv/iconv.c 	err = _php_iconv_substr(&retval, ZSTR_VAL(str), ZSTR_LEN(str), offset, length, charset);