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 multi-
       byte sequence starting at *inbuf to a multibyte sequence starting at *outbuf.  At most *inbytesleft  bytes,  starting  at
       *inbuf, will be read.  At most *outbytesleft 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 rea-
       sons:

       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() 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
       *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.

RETURN VALUE
       The iconv() function returns the number of characters converted in a nonreversible way during this call; reversible  con-
       versions 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 3.25 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)