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(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 start-
       ing 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 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()  func-
       tion 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.

CAVEAT

       The type of inbuf and outbuf, char **, does not imply that the objects pointed to are interpreted as null-terminated C strings or arrays of
       characters.   The  caller of iconv has to make sure that the pointers passed to the function are suitable for access of characters from the
       appropriate character set.  This includes alignment on platforms that have tight restriction on alignment.

RETURN VALUE

       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.

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.

VERSIONS

       This function is available in glibc since version 2.1.

CONFORMING TO

       POSIX.1-2001.

SEE ALSO

       iconv_close(3), iconv_open(3)

COLOPHON

       This  page is part of release 3.27 of the Linux man-pages project.  A description of the project, and information about reporting bugs, can
       be found at http://www.kernel.org/doc/man-pages/.

GNU
								    2008-09-08								  ICONV(3)