| iconvctl - control iconv behavior | 
| #include <iconv.h> int iconvctl (iconv_t cd , int request, void * argument); | 
| The argument cd must be a conversion descriptor created using the function iconv_open. | 
| iconvctl queries or adjusts the behavior of the iconv function, when invoked with the specified conversion descriptor, depending on the request value. | 
| The following are permissible values for the request parameter. | 
| ICONV_TRIVIALP | 
| argument should be an int * which will receive 1 if the conversion is trivial, or 0 otherwise. | 
| ICONV_GET_TRANSLITERATE | 
| argument should be an int * which will receive 1 if transliteration is enabled in the conversion, or 0 otherwise. | 
| ICONV_SET_TRANSLITERATE | 
| argument should be a const int *, pointing to an int value. A non-zero value is used to enable transliteration in the conversion. A zero value disables it. | 
| ICONV_GET_DISCARD_ILSEQ | 
| argument should be an int * which will receive 1 if "illegal sequence discard and continue" is enabled in the conversion, or 0 otherwise. | 
| ICONV_SET_DISCARD_ILSEQ | 
| argument should be a const int *, pointing to an int value. A non-zero value is used to enable "illegal sequence discard and continue" in the conversion. A zero value disables it. | 
| The iconvctl function returns 0 if it succeeds. In case of error, it sets errno and returns -1. | 
| The following errors can occur, among others: | 
| EINVAL | 
| The request is invalid. | 
| This function is implemented only in GNU libiconv and not in other iconv implementations. It is not backed by a standard. You can test for its presence through (_LIBICONV_VERSION >= 0x0108). | 
| iconv_open(3), iconv(3) |