man-pages/man3/iconv_open.3

.\" Copyright (c) Bruno Haible <haible@clisp.cons.org>
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.\" 2007-03-31 Bruno Haible, Describe the glibc/libiconv //TRANSLIT
.\" and //IGNORE extensions for 'tocode'.
.\"
.TH ICONV_OPEN 3  2008-08-11 "GNU" "Linux Programmer's Manual"
.SH NAME
iconv_open \- allocate descriptor for character set conversion
.SH SYNOPSIS
.nf
.B #include <iconv.h>
.sp
.BI "iconv_t iconv_open(const char *" tocode ", const char *" fromcode );
.fi
.SH DESCRIPTION
The
.BR iconv_open ()
function allocates a conversion descriptor suitable
for converting byte sequences from character encoding \fIfromcode\fP to
character encoding \fItocode\fP.
.PP
The values permitted for \fIfromcode\fP and \fItocode\fP and the supported
combinations are system-dependent.
For the GNU C library, the permitted
values are listed by the \fBiconv \-\-list\fP command, and all combinations
of the listed values are supported.
Furthermore the GNU C library and the
GNU libiconv library support the following two suffixes:
.TP
//TRANSLIT
When the string "//TRANSLIT" is appended to \fItocode\fP, transliteration
is activated.
This means that when a character cannot be represented in the
target character set, it can be approximated through one or several
similarly looking characters.
.TP
//IGNORE
When the string "//IGNORE" is appended to \fItocode\fP, characters that
cannot be represented in the target character set will be silently discarded.
.PP
The resulting conversion descriptor can be used with
.BR iconv (3)
any number of times.
It remains valid until deallocated using
.BR iconv_close (3).
.PP
A conversion descriptor contains a conversion state.
After creation using
.BR iconv_open (),
the state is in the initial state.
Using
.BR iconv (3)
modifies the descriptor's conversion state.
(This implies that a conversion
descriptor can not be used in multiple threads simultaneously.)
To bring the state back to the initial state, use
.BR iconv (3)
with NULL as \fIinbuf\fP argument.
.SH "RETURN VALUE"
The
.BR iconv_open ()
function returns a freshly allocated conversion
descriptor.
In case of error, it sets \fIerrno\fP and returns
.IR (iconv_t)\ \-1 .
.SH ERRORS
The following error can occur, among others:
.TP
.B EINVAL
The conversion from \fIfromcode\fP to \fItocode\fP is not supported by the
implementation.
.SH VERSIONS
This function is available in glibc since version 2.1.
.SH "CONFORMING TO"
UNIX98, POSIX.1-2001.
.SH "SEE ALSO"
.BR iconv (1),
.BR iconv (3),
.BR iconv_close (3)