PROLOG

       This  manual  page  is part of the POSIX Programmer's Manual.  The Linux implementation of
       this interface may differ (consult 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 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 .