| iconv - perform character set conversion |
#include <iconv.h>
size_t iconv (iconv_t cd,
const char* * inbuf, size_t * inbytesleft,
char* * outbuf, size_t * outbytesleft);
|
| The argument cd must be a conversion descriptor created using the function iconv_open. |
| The main case is when inbuf is not NULL and *inbuf is not NULL. In this case, the iconv function converts the multibyte sequence starting at *inbuf to a multibyte sequence starting at *outbuf. At most *inbytesleft bytes, starting at *inbuf, will be read. At most *outbytesleft bytes, starting at *outbuf, will be written. |
| The iconv function converts one multibyte character at a time, and for each character conversion it increments *inbuf and decrements *inbytesleft by the number of converted input bytes, it increments *outbuf and decrements *outbytesptr by the number of converted output bytes, and it updates the conversion state contained in cd. The conversion can stop for four reasons: |
| 1. An invalid multibyte sequence is encountered in the input. In this case it sets errno to EILSEQ and returns (size_t)(-1). *inbuf is left pointing to the beginning of the invalid multibyte sequence. |
| 2. The input byte sequence has been entirely converted, i.e. *inbytesleft has gone down to 0. In this case iconv returns the number of non-reversible conversions performed during this call. |
| 3. An incomplete multibyte sequence is encountered in the input, and the input byte sequence terminates after it. In this case it sets errno to EINVAL and returns (size_t)(-1). *inbuf is left pointing to the beginning of the incomplete multibyte sequence. |
| 4. The output buffer has no more room for the next converted character. In this case it sets errno to E2BIG and returns (size_t)(-1). |
| A different case is when inbuf is NULL or *inbuf is NULL, but outbuf is not NULL and *outbuf is not NULL. In this case, the iconv function attempts to set cd's conversion state to the initial state and store a corresponding shift sequence at *outbuf. At most *outbytesleft bytes, starting at *outbuf, will be written. If the output buffer has no more room for this reset sequence, it sets errno to E2BIG and returns (size_t)(-1). Otherwise it increments *outbuf and decrements *outbytesptr by the number of bytes written. |
| A third case is when inbuf is NULL or *inbuf is NULL, and outbuf is NULL or *outbuf is NULL. In this case, the iconv function sets cd's conversion state to the initial state. |
| The iconv function returns the number of characters converted in a non-reversible way during this call; reversible conversions are not counted. In case of error, it sets errno and returns (iconv_t)(-1). |
| The following errors can occur, among others: |
| E2BIG |
| There is not sufficient room at *outbuf. |
| EILSEQ |
| An invalid multibyte sequence has been encountered in the input. |
| EINVAL |
| An incomplete multibyte sequence has been encountered in the input. |
| Unix98 |
| iconv_open(3), iconv_close(3) |