diff options
Diffstat (limited to 'devdocs/c/io%2Fungetwc.html')
| -rw-r--r-- | devdocs/c/io%2Fungetwc.html | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/devdocs/c/io%2Fungetwc.html b/devdocs/c/io%2Fungetwc.html new file mode 100644 index 00000000..88d39fd7 --- /dev/null +++ b/devdocs/c/io%2Fungetwc.html @@ -0,0 +1,27 @@ + <h1 id="firstHeading" class="firstHeading">ungetwc</h1> <table class="t-dcl-begin"> <tr class="t-dsc-header"> <th> Defined in header <code><wchar.h></code> </th> <th> </th> <th> </th> </tr> <tr class="t-dcl"> <td> <pre data-language="c">wint_t ungetwc( wint_t ch, FILE *stream );</pre> +</td> <td class="t-dcl-nopad"> </td> <td> <span class="t-mark-rev t-since-c95">(since C95)</span> </td> </tr> </table> <p>If <code>ch</code> does not equal <code>WEOF</code>, pushes the wide character <code>ch</code> into the input buffer associated with the stream <code>stream</code> in such a manner that subsequent read operation from <code>stream</code> will retrieve that wide character. The external device associated with the stream is not modified.</p> +<p>Stream repositioning operations <code><a href="fseek" title="c/io/fseek">fseek</a></code>, <code><a href="fsetpos" title="c/io/fsetpos">fsetpos</a></code>, and <code><a href="rewind" title="c/io/rewind">rewind</a></code> discard the effects of <code>ungetwc</code>.</p> +<p>If <code>ungetwc</code> is called more than once without an intervening read or repositioning, it may fail (in other words, a pushback buffer of size 1 is guaranteed, but any larger buffer is implementation-defined). If multiple successful <code>ungetwc</code> were performed, read operations retrieve the pushed-back wide characters in reverse order of <code>ungetwc</code></p> +<p>If <code>ch</code> equals <code>WEOF</code>, the operation fails and the stream is not affected.</p> +<p>A successful call to <code>ungetwc</code> clears the end of file status flag <code><a href="feof" title="c/io/feof">feof</a></code>.</p> +<p>A successful call to <code>ungetwc</code> on a stream (whether text or binary) modifies the stream position indicator in unspecified manner but guarantees that after all pushed-back wide characters are retrieved with a read operation, the stream position indicator is equal to its value before <code>ungetwc</code>.</p> +<h3 id="Parameters"> Parameters</h3> <table class="t-par-begin"> <tr class="t-par"> <td> ch </td> <td> - </td> <td> wide character to be put back </td> +</tr> <tr class="t-par"> <td> stream </td> <td> - </td> <td> file stream to put the wide character back to </td> +</tr> +</table> <h3 id="Return_value"> Return value</h3> <p>On success <code>ch</code> is returned.</p> +<p>On failure <code>WEOF</code> is returned and the given stream remains unchanged.</p> +<h3 id="References"> References</h3> <ul> +<li> C11 standard (ISO/IEC 9899:2011): </li> +<ul><li> 7.29.3.10 The ungetwc function (p: 425-426) </li></ul> +<li> C99 standard (ISO/IEC 9899:1999): </li> +<ul><li> 7.24.3.10 The ungetwc function (p: 370-371) </li></ul> +</ul> <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td> <div><a href="ungetc" title="c/io/ungetc"> <span class="t-lines"><span>ungetc</span></span></a></div> </td> <td> puts a character back into a file stream <br> <span class="t-mark">(function)</span> </td> +</tr> <tr class="t-dsc"> <td> <div><a href="fgetwc" title="c/io/fgetwc"> <span class="t-lines"><span>fgetwc</span><span>getwc</span></span></a></div> +<div><span class="t-lines"><span><span class="t-mark-rev t-since-c95">(C95)</span></span></span></div> </td> <td> gets a wide character from a file stream <br> <span class="t-mark">(function)</span> </td> +</tr> <tr class="t-dsc"> <td colspan="2"> <span><a href="https://en.cppreference.com/w/cpp/io/c/ungetwc" title="cpp/io/c/ungetwc">C++ documentation</a></span> for <code>ungetwc</code> </td> +</tr> </table> <div class="_attribution"> + <p class="_attribution-p"> + © cppreference.com<br>Licensed under the Creative Commons Attribution-ShareAlike Unported License v3.0.<br> + <a href="https://en.cppreference.com/w/c/io/ungetwc" class="_attribution-link">https://en.cppreference.com/w/c/io/ungetwc</a> + </p> +</div> |