1ICONV(3)                   Linux Programmer's Manual                  ICONV(3)
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NAME

6       iconv - perform character set conversion
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SYNOPSIS

9       #include <iconv.h>
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11       size_t iconv(iconv_t cd,
12                     char **inbuf, size_t *inbytesleft,
13                     char **outbuf, size_t *outbytesleft);
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DESCRIPTION

16       The argument cd must be a conversion descriptor created using the func‐
17       tion iconv_open().
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19       The main case is when inbuf is not NULL and *inbuf  is  not  NULL.   In
20       this  case, the iconv() function converts the multibyte sequence start‐
21       ing at *inbuf to a multibyte sequence starting  at  *outbuf.   At  most
22       *inbytesleft  bytes,  starting  at *inbuf, will be read.  At most *out‐
23       bytesleft bytes, starting at *outbuf, will be written.
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25       The iconv() function converts one multibyte character at  a  time,  and
26       for  each  character  conversion  it  increments  *inbuf and decrements
27       *inbytesleft by the number of  converted  input  bytes,  it  increments
28       *outbuf  and decrements *outbytesleft by the number of converted output
29       bytes, and it updates the conversion state contained in cd.   The  con‐
30       version can stop for four reasons:
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32       1.  An  invalid multibyte sequence is encountered in the input. In this
33       case it sets errno to EILSEQ and returns (size_t)(-1). *inbuf  is  left
34       pointing to the beginning of the invalid multibyte sequence.
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36       2.   The   input  byte  sequence  has  been  entirely  converted,  i.e.
37       *inbytesleft has gone down to 0. In this case iconv() returns the  num‐
38       ber of non-reversible conversions performed during this call.
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40       3.  An  incomplete  multibyte sequence is encountered in the input, and
41       the input byte sequence terminates after it. In this case it sets errno
42       to  EINVAL  and  returns  (size_t)(-1).  *inbuf is left pointing to the
43       beginning of the incomplete multibyte sequence.
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45       4. The output buffer has no more room for the next converted character.
46       In this case it sets errno to E2BIG and returns (size_t)(-1).
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48       A different case is when inbuf is NULL or *inbuf is NULL, but outbuf is
49       not NULL and *outbuf is not NULL. In this case,  the  iconv()  function
50       attempts  to set cd's conversion state to the initial state and store a
51       corresponding shift sequence at *outbuf.  At most *outbytesleft  bytes,
52       starting at *outbuf, will be written.  If the output buffer has no more
53       room for this reset sequence,  it  sets  errno  to  E2BIG  and  returns
54       (size_t)(-1).  Otherwise  it  increments  *outbuf  and decrements *out‐
55       bytesleft by the number of bytes written.
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57       A third case is when inbuf is NULL or *inbuf is  NULL,  and  outbuf  is
58       NULL  or  *outbuf is NULL. In this case, the iconv() function sets cd's
59       conversion state to the initial state.
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RETURN VALUE

62       The iconv() function returns the number of characters  converted  in  a
63       non-reversible  way  during  this  call; reversible conversions are not
64       counted.  In case of error, it sets errno and returns (size_t)(-1).
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ERRORS

67       The following errors can occur, among others:
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69       E2BIG  There is not sufficient room at *outbuf.
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71       EILSEQ An invalid multibyte sequence has been encountered in the input.
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73       EINVAL An incomplete multibyte sequence has  been  encountered  in  the
74              input.
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CONFORMING TO

77       POSIX.1-2001.
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SEE ALSO

80       iconv_close(3), iconv_open(3)
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84GNU                               2001-11-15                          ICONV(3)