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diff --git a/devdocs/c/io%2Ffwide.html b/devdocs/c/io%2Ffwide.html new file mode 100644 index 00000000..4918f246 --- /dev/null +++ b/devdocs/c/io%2Ffwide.html @@ -0,0 +1,97 @@ + <h1 id="firstHeading" class="firstHeading">fwide</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">int fwide( FILE *stream, int mode );</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>mode > 0</code>, attempts to make <code>stream</code> wide-oriented. If <code>mode < 0</code>, attempts to make <code>stream</code> byte-oriented. If <code>mode==0</code>, only queries the current orientation of the stream.</p> +<p>If the orientation of the stream has already been decided (by executing output or by an earlier call to fwide), this function does nothing.</p> +<h3 id="Parameters"> Parameters</h3> <table class="t-par-begin"> <tr class="t-par"> <td> stream </td> <td> - </td> <td> pointer to the C I/O stream to modify or query </td> +</tr> <tr class="t-par"> <td> mode </td> <td> - </td> <td> integer value greater than zero to set the stream wide, less than zero to set the stream narrow, or zero to query only </td> +</tr> +</table> <h3 id="Return_value"> Return value</h3> <p>An integer greater than zero if the stream is wide-oriented after this call, less than zero if the stream is byte-oriented after this call, and zero if the stream has no orientation.</p> +<h3 id="Example"> Example</h3> <div class="t-example"> +<p>The following code sets and resets the stream orientation.</p> +<div class="c source-c"><pre data-language="c">#include <wchar.h> +#include <stdio.h> +#include <stdlib.h> + +void show_orientation(int n) +{ + n < 0 ? puts("\tnarrow orientation"): + n > 0 ? puts("\twide orientation"): + puts("\tno orientation"); +} + +void try_read(FILE* fp) +{ + int c = fgetc(fp); + if(c == EOF) + puts("\tnarrow character read failed"); + else + printf("\tnarrow character read '%c'\n", c); + + wint_t wc = fgetwc(fp); + if(wc == WEOF) + puts("\twide character read failed"); + else + printf("\twide character read '%lc'\n", wc); +} + +int main(void) +{ + enum fwide_orientation { narrow = -1, query, wide }; + + FILE* fp = fopen("main.cpp", "r"); + if (!fp) + { + perror("fopen() failed"); + return EXIT_FAILURE; + } + + puts("1) A newly opened stream has no orientation."); + show_orientation(fwide(fp, query)); + + puts("2) Establish byte orientation."); + show_orientation(fwide(fp, narrow)); + try_read(fp); + + puts("3) Only freopen() can reset stream orientation."); + if (freopen("main.cpp", "r", fp) == NULL) + { + perror("freopen() failed"); + return EXIT_FAILURE; + } + + puts("4) A reopened stream has no orientation."); + show_orientation(fwide(fp, query)); + + puts("5) Establish wide orientation."); + show_orientation(fwide(fp, wide)); + try_read(fp); + + fclose(fp); +}</pre></div> <p>Possible output:</p> +<div class="text source-text"><pre data-language="c">1) A newly opened stream has no orientation. + no orientation +2) Establish byte orientation. + narrow orientation + narrow character read '#' + wide character read failed +3) Only freopen() can reset stream orientation. +4) A reopened stream has no orientation. + no orientation +5) Establish wide orientation. + wide orientation + narrow character read failed + wide character read '#'</pre></div> </div> <h3 id="References"> References</h3> <ul> +<li> C17 standard (ISO/IEC 9899:2018): </li> +<ul><li> 7.29.3.5 The fwide function (p: 309) </li></ul> +<li> C11 standard (ISO/IEC 9899:2011): </li> +<ul><li> 7.29.3.5 The fwide function (p: 423) </li></ul> +<li> C99 standard (ISO/IEC 9899:1999): </li> +<ul><li> 7.24.3.5 The fwide function (p: 369) </li></ul> +</ul> <h3 id="See_also"> See also</h3> <table class="t-dsc-begin"> <tr class="t-dsc"> <td> <div><a href="fopen" title="c/io/fopen"> <span class="t-lines"><span>fopen</span><span>fopen_s</span></span></a></div> +<div><span class="t-lines"><span><span class="t-mark-rev t-since-c11">(C11)</span></span></span></div> </td> <td> opens a file <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/fwide" title="cpp/io/c/fwide">C++ documentation</a></span> for <code>fwide</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/fwide" class="_attribution-link">https://en.cppreference.com/w/c/io/fwide</a> + </p> +</div> |