iconv

ICONV(3)		  Linux Programmer’s Manual		     ICONV(3)



NAME
       iconv - perform character set conversion

SYNOPSIS
       #include <iconv.h>

       size_t iconv(iconv_t cd,
		     char **inbuf, size_t *inbytesleft,
		     char **outbuf, size_t *outbytesleft);

DESCRIPTION
       The  argument  cd  must	be  a conversion descriptor created using the
       function 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.  The	 con-
       version 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  charac-
       ter. 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
       UNIX98

SEE ALSO
       iconv_open(3), iconv_close(3)



GNU				  2001-11-15			     ICONV(3)