67 lines
1.9 KiB
HTML
67 lines
1.9 KiB
HTML
<!DOCTYPE html>
|
|
<html lang="en">
|
|
<head>
|
|
<meta charset="UTF-8">
|
|
<link rel="stylesheet" type="text/css" href="mystyle.css">
|
|
<meta name="viewport" content="width=device-width, initial-scale=1.0">
|
|
<meta name="keywords" content="loops, while, unix, shell">
|
|
<meta name="author" content="Aleksandar Todorovic">
|
|
<meta http-equiv="X-UA-Compatible" content="ie=edge">
|
|
<title>while|loops</title>
|
|
</head>
|
|
<body>
|
|
<header>
|
|
<div class="nav">
|
|
<ul>
|
|
<li><a href="index.html">home</a></li>
|
|
<li><a href="index_if.html">if</a>
|
|
<ul>
|
|
<li><a href="if.html"></a>if-fi</li>
|
|
<li><a href="if-else.html"></a>if-else</li>
|
|
<li><a href="elif.html"></a>if-elif</li>
|
|
</ul>
|
|
</li>
|
|
<li><a href="loops_index.html">Loops</a>
|
|
<ul>
|
|
<li class="current"><a href="while.html"></a>while</li>
|
|
<li><a href="for.html"></a>for</li>
|
|
</ul>
|
|
</li>
|
|
</ul>
|
|
</div>
|
|
</header>
|
|
<div class="syntax">
|
|
<h2>syntax of While Loops</h2>
|
|
<P>#!/bin/sh <br>
|
|
while [ comand ] <br>
|
|
do <br>
|
|
statement to be exeuted if command is true <br>
|
|
done <br>
|
|
</P>
|
|
|
|
<h2>Exemple</h2>
|
|
#!/bin/sh <br>
|
|
INPUT_STRING=hello <br>
|
|
while [ "$INPUT_STRING"!="bye" ] <br>
|
|
do <br>
|
|
echo "please type something in (bye to quit) <br>
|
|
read INPUT_STRING <br>
|
|
echo "You typed: $INPUT_STRING" <br>
|
|
done <br>
|
|
|
|
<h3>Explanation</h3>
|
|
<P>In this exemple "echo" and read statement run will go forward until we type "bye" <br>
|
|
Normaly "while" command execute a code if this expression code is true, and stop only when is false or when say (type) stop.</P>
|
|
|
|
</div>
|
|
<footer>
|
|
<h4>Source</h4>
|
|
<ul>
|
|
<li>https://www.shellscript.sh/loops.html</li>
|
|
<li>https://www.autistici.org/loa/shodan/corsounix.pdf</li>
|
|
<li>https://www.guru4technoworld.wix.com</li>
|
|
</ul>
|
|
</footer>
|
|
</body>
|
|
</html>
|