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(3).
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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.   If  the
30       character  encoding  of the input is stateful, the iconv() function can
31       also convert a sequence of input bytes to an update to  the  conversion
32       state  without producing any output bytes; such input is called a shift
33       sequence.  The conversion can stop for four reasons:
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35       1. An invalid multibyte sequence is encountered in the input.  In  this
36       case  it  sets errno to EILSEQ and returns (size_t) -1.  *inbuf is left
37       pointing to the beginning of the invalid multibyte sequence.
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39       2. The input byte  sequence  has  been  entirely  converted,  that  is,
40       *inbytesleft has gone down to 0.  In this case iconv() returns the num‐
41       ber of nonreversible conversions performed during this call.
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43       3. An incomplete multibyte sequence is encountered in  the  input,  and
44       the  input  byte  sequence  terminates  after it.  In this case it sets
45       errno to EINVAL and returns (size_t) -1.  *inbuf is  left  pointing  to
46       the beginning of the incomplete multibyte sequence.
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48       4. The output buffer has no more room for the next converted character.
49       In this case it sets errno to E2BIG and returns (size_t) -1.
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51       A different case is when inbuf is NULL or *inbuf is NULL, but outbuf is
52       not  NULL  and *outbuf is not NULL.  In this case, the iconv() function
53       attempts to set cd's conversion state to the initial state and store  a
54       corresponding  shift sequence at *outbuf.  At most *outbytesleft bytes,
55       starting at *outbuf, will be written.  If the output buffer has no more
56       room  for  this  reset  sequence,  it  sets  errno to E2BIG and returns
57       (size_t) -1.  Otherwise it  increments  *outbuf  and  decrements  *out‐
58       bytesleft by the number of bytes written.
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60       A  third  case  is  when inbuf is NULL or *inbuf is NULL, and outbuf is
61       NULL or *outbuf is NULL.  In this case, the iconv() function sets  cd's
62       conversion state to the initial state.
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RETURN VALUE

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

70       The following errors can occur, among others:
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72       E2BIG  There is not sufficient room at *outbuf.
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74       EILSEQ An invalid multibyte sequence has been encountered in the input.
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76       EINVAL An  incomplete  multibyte  sequence  has been encountered in the
77              input.
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VERSIONS

80       This function is available in glibc since version 2.1.
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CONFORMING TO

83       POSIX.1-2001.
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SEE ALSO

86       iconv_close(3), iconv_open(3)
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COLOPHON

89       This page is part of release 3.25 of the Linux  man-pages  project.   A
90       description  of  the project, and information about reporting bugs, can
91       be found at http://www.kernel.org/doc/man-pages/.
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95GNU                               2008-09-08                          ICONV(3)
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