The Open Group Base Specifications Issue 7, 2018 edition
IEEE Std 1003.1-2017 (Revision of IEEE Std 1003.1-2008)
Copyright © 2001-2018 IEEE and The Open Group

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

XBD <fcntl.h>, <iconv.h>

CHANGE HISTORY

First released in Issue 4. Derived from the HP-UX Manual.

Issue 7

SD5-XBD-ERN-4 is applied, changing the definition of the [EMFILE] error.

The iconv_open() function is moved from the XSI option to the Base.

End of informative text.

 

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