1<html lang="en"> 2<head> 3<title>islower - 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="Ctype.html#Ctype" title="Ctype"> 9<link rel="prev" href="isdigit.html#isdigit" title="isdigit"> 10<link rel="next" href="isprint.html#isprint" title="isprint"> 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="islower"></a> 29<p> 30Next: <a rel="next" accesskey="n" href="isprint.html#isprint">isprint</a>, 31Previous: <a rel="previous" accesskey="p" href="isdigit.html#isdigit">isdigit</a>, 32Up: <a rel="up" accesskey="u" href="Ctype.html#Ctype">Ctype</a> 33<hr> 34</div> 35 36<h3 class="section">3.6 <code>islower</code>—lowercase character predicate</h3> 37 38<p><a name="index-islower-115"></a><strong>Synopsis</strong> 39<pre class="example"> #include <ctype.h> 40 int islower(int <var>c</var>); 41 42</pre> 43 <p><strong>Description</strong><br> 44<code>islower</code> is a macro which classifies ASCII integer values by table 45lookup. It is a predicate returning non-zero for minuscules 46(lowercase alphabetic characters), and 0 for other characters. 47It is defined only if <var>c</var> is representable as an unsigned char or if 48<var>c</var> is EOF. 49 50 <p>You can use a compiled subroutine instead of the macro definition by 51undefining the macro using `<code>#undef islower</code>'. 52 53 <p><br> 54<strong>Returns</strong><br> 55<code>islower</code> returns non-zero if <var>c</var> is a lowercase letter (<code>a</code>–<code>z</code>). 56 57 <p><br> 58<strong>Portability</strong><br> 59<code>islower</code> is ANSI C. 60 61 <p>No supporting OS subroutines are required. 62 63 <p><br> 64 65 </body></html> 66 67