You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

fwide.html 4.4KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106
  1. <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
  2. <html>
  3. <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
  4. <head>
  5. <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
  6. <title>fwide (The Red Hat newlib C Library)</title>
  7. <meta name="description" content="fwide (The Red Hat newlib C Library)">
  8. <meta name="keywords" content="fwide (The Red Hat newlib C Library)">
  9. <meta name="resource-type" content="document">
  10. <meta name="distribution" content="global">
  11. <meta name="Generator" content="makeinfo">
  12. <link href="index.html#Top" rel="start" title="Top">
  13. <link href="Document-Index.html#Document-Index" rel="index" title="Document Index">
  14. <link href="Document-Index.html#SEC_Contents" rel="contents" title="Table of Contents">
  15. <link href="Stdio.html#Stdio" rel="up" title="Stdio">
  16. <link href="fwrite.html#fwrite" rel="next" title="fwrite">
  17. <link href="funopen.html#funopen" rel="prev" title="funopen">
  18. <style type="text/css">
  19. <!--
  20. a.summary-letter {text-decoration: none}
  21. blockquote.indentedblock {margin-right: 0em}
  22. blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
  23. blockquote.smallquotation {font-size: smaller}
  24. div.display {margin-left: 3.2em}
  25. div.example {margin-left: 3.2em}
  26. div.lisp {margin-left: 3.2em}
  27. div.smalldisplay {margin-left: 3.2em}
  28. div.smallexample {margin-left: 3.2em}
  29. div.smalllisp {margin-left: 3.2em}
  30. kbd {font-style: oblique}
  31. pre.display {font-family: inherit}
  32. pre.format {font-family: inherit}
  33. pre.menu-comment {font-family: serif}
  34. pre.menu-preformatted {font-family: serif}
  35. pre.smalldisplay {font-family: inherit; font-size: smaller}
  36. pre.smallexample {font-size: smaller}
  37. pre.smallformat {font-family: inherit; font-size: smaller}
  38. pre.smalllisp {font-size: smaller}
  39. span.nolinebreak {white-space: nowrap}
  40. span.roman {font-family: initial; font-weight: normal}
  41. span.sansserif {font-family: sans-serif; font-weight: normal}
  42. ul.no-bullet {list-style: none}
  43. -->
  44. </style>
  45. </head>
  46. <body lang="en">
  47. <a name="fwide"></a>
  48. <div class="header">
  49. <p>
  50. Next: <a href="fwrite.html#fwrite" accesskey="n" rel="next">fwrite</a>, Previous: <a href="funopen.html#funopen" accesskey="p" rel="prev">funopen</a>, Up: <a href="Stdio.html#Stdio" accesskey="u" rel="up">Stdio</a> &nbsp; [<a href="Document-Index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Document-Index.html#Document-Index" title="Index" rel="index">Index</a>]</p>
  51. </div>
  52. <hr>
  53. <a name="fwide_002d_002d_002dset-and-determine-the-orientation-of-a-FILE-stream"></a>
  54. <h3 class="section">4.31 <code>fwide</code>&mdash;set and determine the orientation of a FILE stream</h3>
  55. <a name="index-fwide"></a>
  56. <a name="index-_005ffwide_005fr"></a>
  57. <p><strong>Synopsis</strong>
  58. </p><div class="example">
  59. <pre class="example">#include &lt;wchar.h&gt;
  60. int fwide(FILE *<var>fp</var>, int <var>mode</var>);
  61. int _fwide_r(struct _reent *<var>ptr</var>, FILE *<var>fp</var>, int <var>mode</var>);
  62. </pre></div>
  63. <p><strong>Description</strong><br>
  64. When <var>mode</var> is zero, the <code>fwide</code> function determines the current
  65. orientation of <var>fp</var>. It returns a value &gt; 0 if <var>fp</var> is
  66. wide-character oriented, i.e. if wide character I/O is permitted but
  67. char I/O is disallowed. It returns a value &lt; 0 if <var>fp</var> is byte
  68. oriented, i.e. if char I/O is permitted but wide character I/O is
  69. disallowed. It returns zero if <var>fp</var> has no orientation yet; in
  70. this case the next I/O operation might change the orientation (to byte
  71. oriented if it is a char I/O operation, or to wide-character oriented
  72. if it is a wide character I/O operation).
  73. </p>
  74. <p>Once a stream has an orientation, it cannot be changed and persists
  75. until the stream is closed, unless the stream is re-opened with freopen,
  76. which removes the orientation of the stream.
  77. </p>
  78. <p>When <var>mode</var> is non-zero, the <code>fwide</code> function first attempts to set
  79. <var>fp</var>&rsquo;s orientation (to wide-character oriented if <var>mode</var> &gt; 0, or to
  80. byte oriented if <var>mode</var> &lt; 0). It then returns a value denoting the
  81. current orientation, as above.
  82. </p>
  83. <br>
  84. <p><strong>Returns</strong><br>
  85. The <code>fwide</code> function returns <var>fp</var>&rsquo;s orientation, after possibly
  86. changing it. A return value &gt; 0 means wide-character oriented. A return
  87. value &lt; 0 means byte oriented. A return value of zero means undecided.
  88. </p>
  89. <br>
  90. <p><strong>Portability</strong><br>
  91. C99, POSIX.1-2001.
  92. </p>
  93. <br>
  94. </body>
  95. </html>