ICONV_OPEN(3P)                                      POSIX Programmer's Manual                                     ICONV_OPEN(3P)



PROLOG
       This  manual  page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (con-
       sult the corresponding Linux manual page for details of Linux behavior), or the  interface  may  not  be  implemented  on
       Linux.

NAME
       iconv_open - codeset conversion allocation function

SYNOPSIS
       #include <iconv.h>

       iconv_t iconv_open(const char *tocode, const char *fromcode);


DESCRIPTION
       The  iconv_open() function shall return a conversion descriptor that describes a conversion from the codeset specified by
       the string pointed to by the fromcode argument to the codeset specified by the string pointed to by the tocode  argument.
       For  state-dependent  encodings, the conversion descriptor shall be in a codeset-dependent initial shift state, ready for
       immediate use with iconv().

       Settings of fromcode and tocode and their permitted combinations are implementation-defined.

       A conversion descriptor shall remain valid until it is closed by iconv_close() or an implicit close.

       If a file descriptor is used to implement conversion descriptors, the FD_CLOEXEC flag shall be set; see <fcntl.h>.

RETURN VALUE
       Upon successful completion, iconv_open() shall return a conversion descriptor for use on  subsequent  calls  to  iconv().
       Otherwise, iconv_open() shall return (iconv_t)-1 and set errno to indicate the error.

ERRORS
       The iconv_open() function may fail if:

       EMFILE {OPEN_MAX} file descriptors are currently open in the calling process.

       ENFILE Too many files are currently open in the system.

       ENOMEM Insufficient storage space is available.

       EINVAL The conversion specified by fromcode and tocode is not supported by the implementation.


       The following sections are informative.

EXAMPLES
       None.

APPLICATION USAGE
       Some  implementations of iconv_open() use malloc() to allocate space for internal buffer areas. The iconv_open() function
       may fail if there is insufficient storage space to accommodate these buffers.

       Conforming applications must assume that conversion descriptors are not valid after a call to one of the exec functions.

       Application developers should consult the system documentation to determine  the  supported  codesets  and  their  naming
       schemes.

RATIONALE
       None.

FUTURE DIRECTIONS
       None.

SEE ALSO
       iconv(), iconv_close(), the Base Definitions volume of IEEE Std 1003.1-2001, <fcntl.h>, <iconv.h>

COPYRIGHT
       Portions  of  this  text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for
       Information Technology -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6,  Copy-
       right (C) 2001-2003 by the Institute of Electrical and Electronics Engineers, Inc and The Open Group. In the event of any
       discrepancy between this version and the original IEEE and The Open Group Standard, the original IEEE and The Open  Group
       Standard   is   the   referee   document.   The   original   Standard   can   be   obtained  online  at  http://www.open-
       group.org/unix/online.html .



IEEE/The Open Group                                           2003                                                ICONV_OPEN(3P)