iconv — perform character set conversion
#include <iconv.h>
size_t iconv( |
iconv_t | cd, |
char ** | inbuf, | |
size_t * | inbytesleft, | |
char ** | outbuf, | |
size_t * | outbytesleft) ; |
The argument cd
must be a conversion descriptor created using the function
iconv_open(3).
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
*outbytesleft
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,
that is, *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
*outbytesleft
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 (size_t)(−1)
.
The following errors can occur, among others:
There is not sufficient room at *outbuf
.
An invalid multibyte sequence has been encountered in the input.
An incomplete multibyte sequence has been encountered in the input.
Copyright (c) Bruno Haible <haibleclisp.cons.org> This is free documentation; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. References consulted: GNU glibc-2 source code and manual OpenGroup's Single Unix specification http://www.UNIX-systems.org/online.html 2000-06-30 correction by Yuichi SATO <satocomplex.eng.hokudai.ac.jp> 2000-11-15 aeb, fixed prototype |