ICONV(3) Linux Programmer's Manual ICONV(3)NAMEiconv - perform character set conversion
SYNOPSIS
#include <iconv.h>
size_t iconv (iconv_t cd,
const char* * inbuf, size_t * inbytesleft,
char* * outbuf, size_t * outbytesleft);
DESCRIPTION
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 con
verted 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 con
version 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 con
verted 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, start
ing 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.
RETURN VALUE
The iconv function returns the number of characters con
verted 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).
ERRORS
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 encoun
tered in the input.
CONFORMING TO
UNIX98
SEE ALSOiconv_open(3), iconv_close(3)GNU November 18, 2000 ICONV(3)
