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. If the character encoding
      of the input is stateful, the iconv() function can also convert a
      sequence of input bytes to an update to the conversion state
      without producing any output bytes; such input is called a
      shift sequence. 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 nonreversible
      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 nonreversible 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.
This page is part of release 3.33 of the Linux man-pages project. A
      description of the project, and information about reporting
      bugs, can be found at http://man7.org/linux/man-pages/.
| 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 |