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iconv(3)                   Linux Programmer's Manual                  iconv(3)




NAME

       iconv - 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 func-
       tion 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 *out-
       bytesleft 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 of  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,   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 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  *out-
       bytesleft 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 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).


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  encountered  in  the
              input.


CONFORMING TO

       POSIX:2001


SEE ALSO

       iconv_open(3), iconvctl(3) iconv_close(3)



GNU                            September 7, 2008                      iconv(3)

libiconv 1.14 - Generated Mon Aug 8 13:56:06 CDT 2011
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