1<html lang="en"> 2<head> 3<title>ferror - Untitled</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="Untitled"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="up" href="Stdio.html#Stdio" title="Stdio"> 9<link rel="prev" href="feof.html#feof" title="feof"> 10<link rel="next" href="fflush.html#fflush" title="fflush"> 11<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 12<meta http-equiv="Content-Style-Type" content="text/css"> 13<style type="text/css"><!-- 14 pre.display { font-family:inherit } 15 pre.format { font-family:inherit } 16 pre.smalldisplay { font-family:inherit; font-size:smaller } 17 pre.smallformat { font-family:inherit; font-size:smaller } 18 pre.smallexample { font-size:smaller } 19 pre.smalllisp { font-size:smaller } 20 span.sc { font-variant:small-caps } 21 span.roman { font-family:serif; font-weight:normal; } 22 span.sansserif { font-family:sans-serif; font-weight:normal; } 23--></style> 24<link rel="stylesheet" type="text/css" href="../cs.css"> 25</head> 26<body> 27<div class="node"> 28<a name="ferror"></a> 29<p> 30Next: <a rel="next" accesskey="n" href="fflush.html#fflush">fflush</a>, 31Previous: <a rel="previous" accesskey="p" href="feof.html#feof">feof</a>, 32Up: <a rel="up" accesskey="u" href="Stdio.html#Stdio">Stdio</a> 33<hr> 34</div> 35 36<h3 class="section">4.8 <code>ferror</code>—test whether read/write error has occurred</h3> 37 38<p><a name="index-ferror-161"></a><strong>Synopsis</strong> 39<pre class="example"> #include <stdio.h> 40 int ferror(FILE *<var>fp</var>); 41 42</pre> 43 <p><strong>Description</strong><br> 44The <code>stdio</code> functions maintain an error indicator with each file 45pointer <var>fp</var>, to record whether any read or write errors have 46occurred on the associated file or stream. 47Use <code>ferror</code> to query this indicator. 48 49 <p>See <code>clearerr</code> to reset the error indicator. 50 51 <p><br> 52<strong>Returns</strong><br> 53<code>ferror</code> returns <code>0</code> if no errors have occurred; it returns a 54nonzero value otherwise. 55 56 <p><br> 57<strong>Portability</strong><br> 58ANSI C requires <code>ferror</code>. 59 60 <p>No supporting OS subroutines are required. 61 62 <p><br> 63 64 </body></html> 65 66