|ICONV(3P)||POSIX Programmer's Manual||ICONV(3P)|
size_t iconv(iconv_t cd, char **restrict inbuf, size_t *restrict inbytesleft, char **restrict outbuf, size_t *restrict outbytesleft);
For state-dependent encodings, the conversion descriptor cd is placed into its initial shift state by a call for which inbuf is a null pointer, or for which inbuf points to a null pointer. When iconv() is called in this way, and if outbuf is not a null pointer or a pointer to a null pointer, and outbytesleft points to a positive value, iconv() shall place, into the output buffer, the byte sequence to change the output buffer to its initial shift state. If the output buffer is not large enough to hold the entire reset sequence, iconv() shall fail and set errno to [E2BIG]. Subsequent calls with inbuf as other than a null pointer or a pointer to a null pointer cause the conversion to take place from the current state of the conversion descriptor.
If a sequence of input bytes does not form a valid character in the specified codeset, conversion shall stop after the previous successfully converted character. If the input buffer ends with an incomplete character or shift sequence, conversion shall stop after the previous successfully converted bytes. If the output buffer is not large enough to hold the entire converted input, conversion shall stop just prior to the input bytes that would cause the output buffer to overflow. The variable pointed to by inbuf shall be updated to point to the byte following the last byte successfully used in the conversion. The value pointed to by inbytesleft shall be decremented to reflect the number of bytes still not converted in the input buffer. The variable pointed to by outbuf shall be updated to point to the byte following the last byte of converted output data. The value pointed to by outbytesleft shall be decremented to reflect the number of bytes still available in the output buffer. For state-dependent encodings, the conversion descriptor shall be updated to reflect the shift state in effect at the end of the last successfully converted byte sequence.
If iconv() encounters a character in the input buffer that is valid, but for which an identical character does not exist in the target codeset, iconv() shall perform an implementation-defined conversion on this character.
- Input conversion stopped due to an input byte that does not belong to the input codeset.
- Input conversion stopped due to lack of space in the output buffer.
- Input conversion stopped due to an incomplete character or shift sequence at the end of the input buffer.
The iconv() function may fail if:
- The cd argument is not a valid open conversion descriptor.
The following sections are informative.
Regardless of the data type inferred by the converter, the size of the remaining space in both input and output objects (the intbytesleft and outbytesleft arguments) is always measured in bytes.
For implementations that support the conversion of state-dependent encodings, the conversion descriptor must be able to accurately reflect the shift-state in effect at the end of the last successful conversion. It is not required that the conversion descriptor itself be updated, which would require it to be a pointer type. Thus, implementations are free to implement the descriptor as a handle (other than a pointer type) by which the conversion information can be accessed and updated.
The Base Definitions volume of POSIX.1‐2017, <iconv.h>
Any typographical or formatting errors that appear in this page are most likely to have been introduced during the conversion of the source files to man page format. To report such errors, see https://www.kernel.org/doc/man-pages/reporting_bugs.html .
|2017||IEEE/The Open Group|