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



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

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 All file descriptors available to the process are currently
              open.

       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 POSIX.1-2017, <fcntl.h>, <iconv.h>

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form
       from IEEE Std 1003.1-2017, Standard for Information Technology --
       Portable Operating System Interface (POSIX), The Open Group Base
       Specifications Issue 7, 2018 Edition, Copyright (C) 2018 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.opengroup.org/unix/online.html .

       Any typographical or formatting errors that appear in this page are
       most likely to have been introduced during the conversion of the source
       files to man page format. To report such errors, see
       https://www.kernel.org/doc/man-pages/reporting_bugs.html .



IEEE/The Open Group                  2017                        ICONV_OPEN(3)
