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| <title>ICONV</title> |
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| <body> |
|
|
| <h1 align="center">ICONV</h1> |
|
|
| <a href="#NAME">NAME</a><br> |
| <a href="#SYNOPSIS">SYNOPSIS</a><br> |
| <a href="#DESCRIPTION">DESCRIPTION</a><br> |
| <a href="#RETURN VALUE">RETURN VALUE</a><br> |
| <a href="#ERRORS">ERRORS</a><br> |
| <a href="#CONFORMING TO">CONFORMING TO</a><br> |
| <a href="#NOTES">NOTES</a><br> |
| <a href="#SEE ALSO">SEE ALSO</a><br> |
|
|
| <hr> |
|
|
|
|
| <h2>NAME |
| <a name="NAME"></a> |
| </h2> |
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em">iconv − |
| perform character set conversion</p> |
|
|
| <h2>SYNOPSIS |
| <a name="SYNOPSIS"></a> |
| </h2> |
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em"><b>#include |
| <iconv.h></b></p> |
|
|
| <p style="margin-left:11%; margin-top: 1em"><b>size_t iconv |
| (iconv_t</b> <i>cd</i><b>, <br> |
| const char* *</b> <i>inbuf</i><b>, size_t *</b> |
| <i>inbytesleft</i><b>, <br> |
| char* *</b> <i>outbuf</i><b>, size_t *</b> |
| <i>outbytesleft</i><b>);</b></p> |
|
|
| <h2>DESCRIPTION |
| <a name="DESCRIPTION"></a> |
| </h2> |
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em">The argument |
| <i>cd</i> must be a conversion descriptor created using the |
| function <b>iconv_open</b>.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">The main case |
| is when <i>inbuf</i> is not NULL and <i>*inbuf</i> is not |
| NULL. In this case, the <b>iconv</b> function converts the |
| multibyte sequence starting at <i>*inbuf</i> to a multibyte |
| sequence starting at <i>*outbuf</i>. At most |
| <i>*inbytesleft</i> bytes, starting at <i>*inbuf</i>, will |
| be read. At most <i>*outbytesleft</i> bytes, starting at |
| <i>*outbuf</i>, will be written.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">The |
| <b>iconv</b> function converts one multibyte character at a |
| time, and for each character conversion it increments |
| <i>*inbuf</i> and decrements <i>*inbytesleft</i> by the |
| number of converted input bytes, it increments |
| <i>*outbuf</i> and decrements <i>*outbytesleft</i> by the |
| number of converted output bytes, and it updates the |
| conversion state contained in <i>cd</i>. If the character |
| encoding of the input is stateful, the <b>iconv</b> function |
| can also convert a sequence of input bytes to an update of |
| the conversion state without producing any output bytes; |
| such input is called a <i>shift sequence</i>. The conversion |
| can stop for five reasons:</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">1. An invalid |
| multibyte sequence is encountered in the input. In this case |
| it sets <b>errno</b> to <b>EILSEQ</b> and returns |
| (size_t)(−1). <i>*inbuf</i> is left pointing to the |
| beginning of the invalid multibyte sequence.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">2. A multibyte |
| sequence is encountered that is valid but that cannot be |
| translated to the character encoding of the output. This |
| condition depends on the implementation and on the |
| conversion descriptor. In the GNU C library and GNU |
| libiconv, if <i>cd</i> was created without the suffix |
| <b>//TRANSLIT</b> or <b>//IGNORE</b> or |
| <b>//NON_IDENTICAL_DISCARD</b>, the conversion is strict: |
| lossy conversions produce this condition. If the suffix |
| <b>//TRANSLIT</b> was specified, transliteration can avoid |
| this condition in some cases. In the musl C library, this |
| condition cannot occur because a conversion to <b>'*'</b> is |
| used as a fallback. In the FreeBSD, NetBSD, and Solaris |
| implementations of <b>iconv</b>, this condition cannot occur |
| either, because a conversion to <b>'?'</b> is used as a |
| fallback. When this condition is met, the <b>iconv</b> |
| function sets <b>errno</b> to <b>EILSEQ</b> and returns |
| (size_t)(−1). <i>*inbuf</i> is left pointing to the |
| beginning of the unconvertible multibyte sequence.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">3. The input |
| byte sequence has been entirely converted, i.e. |
| <i>*inbytesleft</i> has gone down to 0. In this case |
| <b>iconv</b> returns the number of non-reversible |
| conversions performed during this call.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">4. An |
| incomplete multibyte sequence is encountered in the input, |
| and the input byte sequence terminates after it. In this |
| case it sets <b>errno</b> to <b>EINVAL</b> and returns |
| (size_t)(−1). <i>*inbuf</i> is left pointing to the |
| beginning of the incomplete multibyte sequence.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">5. The output |
| buffer has no more room for the next converted character. In |
| this case it sets <b>errno</b> to <b>E2BIG</b> and returns |
| (size_t)(−1).</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">A different |
| case is when <i>inbuf</i> is NULL or <i>*inbuf</i> is NULL, |
| but <i>outbuf</i> is not NULL and <i>*outbuf</i> is not |
| NULL. In this case, the <b>iconv</b> function attempts to |
| set <i>cd</i>’s conversion state to the initial state |
| and store a corresponding shift sequence at <i>*outbuf</i>. |
| At most <i>*outbytesleft</i> bytes, starting at |
| <i>*outbuf</i>, will be written. If the output buffer has no |
| more room for this reset sequence, it sets <b>errno</b> to |
| <b>E2BIG</b> and returns (size_t)(−1). Otherwise it |
| increments <i>*outbuf</i> and decrements |
| <i>*outbytesleft</i> by the number of bytes written.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">A third case is |
| when <i>inbuf</i> is NULL or <i>*inbuf</i> is NULL, and |
| <i>outbuf</i> is NULL or <i>*outbuf</i> is NULL. In this |
| case, the <b>iconv</b> function sets <i>cd</i>’s |
| conversion state to the initial state.</p> |
|
|
| <h2>RETURN VALUE |
| <a name="RETURN VALUE"></a> |
| </h2> |
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em">The |
| <b>iconv</b> function returns the number of characters |
| converted in a non-reversible way during this call; |
| reversible conversions are not counted. In case of error, it |
| sets <b>errno</b> and returns (size_t)(−1).</p> |
|
|
| <h2>ERRORS |
| <a name="ERRORS"></a> |
| </h2> |
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em">The following |
| errors can occur, among others:</p> |
|
|
| <table width="100%" border="0" rules="none" frame="void" |
| cellspacing="0" cellpadding="0"> |
| <tr valign="top" align="left"> |
| <td width="11%"></td> |
| <td width="9%"> |
|
|
|
|
| <p><b>E2BIG</b></p></td> |
| <td width="2%"></td> |
| <td width="78%"> |
|
|
|
|
| <p>There is not sufficient room at <i>*outbuf</i>.</p></td></tr> |
| <tr valign="top" align="left"> |
| <td width="11%"></td> |
| <td width="9%"> |
|
|
|
|
| <p><b>EILSEQ</b></p></td> |
| <td width="2%"></td> |
| <td width="78%"> |
|
|
|
|
| <p>An invalid multibyte sequence has been encountered in |
| the input.</p></td></tr> |
| <tr valign="top" align="left"> |
| <td width="11%"></td> |
| <td width="9%"> |
|
|
|
|
| <p><b>EINVAL</b></p></td> |
| <td width="2%"></td> |
| <td width="78%"> |
|
|
|
|
| <p>An incomplete multibyte sequence has been encountered in |
| the input.</p></td></tr> |
| </table> |
|
|
| <h2>CONFORMING TO |
| <a name="CONFORMING TO"></a> |
| </h2> |
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em">POSIX:2024</p> |
|
|
| <h2>NOTES |
| <a name="NOTES"></a> |
| </h2> |
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em">In each series |
| of calls to the <b>iconv</b> function, the last should be |
| one with <i>inbuf</i> or <i>*inbuf</i> equal to NULL, in |
| order to complete the conversion of any partially converted |
| input.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">Although |
| <i>inbuf</i> and <i>outbuf</i> are typed as <b>const char |
| **</b> and <b>char **</b>, respectively, this does not mean |
| that the objects they point can be interpreted as C strings |
| or as arrays of characters: the interpretation of character |
| byte sequences is handled internally by the conversion |
| functions. In some encodings, a zero byte may be a valid |
| part of a multibyte character.</p> |
|
|
| <p style="margin-left:11%; margin-top: 1em">The caller of |
| the <b>iconv</b> function must ensure that the pointers |
| passed to the function are suitable for accessing characters |
| in the appropriate character set. For the encodings |
| <b>UCS-2-INTERNAL</b>, <b>UCS-4-INTERNAL</b>, and |
| <b>wchar_t</b>, this includes ensuring correct |
| alignment.</p> |
|
|
| <h2>SEE ALSO |
| <a name="SEE ALSO"></a> |
| </h2> |
|
|
|
|
|
|
| <p style="margin-left:11%; margin-top: 1em"><b>iconv_open</b>(3), |
| <b>iconvctl</b>(3), <b>iconv_close</b>(3)</p> |
| <hr> |
| </body> |
| </html> |
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