<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 3.2 Final//EN"> <html> <head> <meta name="generator" content="HTML Tidy, see www.w3.org"> <meta http-equiv="Content-Type" content= "text/html; charset=utf-8"> <title>If command</title> <LINK rel="stylesheet" type="text/css" href="../rzahg/ic.css"> </HEAD> <body bgcolor="#FFFFFF"> <!-- Java sync-link --> <SCRIPT LANGUAGE="Javascript" SRC="../rzahg/synch.js" TYPE="text/javascript"></SCRIPT> <h2>If command</h2> <p>The syntax of the <strong>if</strong> command is</p> <p><strong>if</strong> <em>list1</em></p> <p><strong>then</strong> <em>list2</em></p> <p><strong>[</strong> <strong>elif</strong> <em>list3</em></p> <p><strong>then</strong> <em>list4</em> <strong>]</strong> ...</p> <p><strong>[</strong> <strong>else</strong> <em>list5</em> <strong> ]</strong></p> <p><strong>fi</strong></p> <p>First, <strong>qsh</strong> runs <em>list1</em> and if its exit status is zero then <strong>qsh</strong> runs <em>list2</em>. Otherwise, each elif <em>list3</em> is run and if its exit status is zero then <strong>qsh</strong> runs <em>list4</em>. Otherwise, <strong>qsh</strong> runs <em>list5</em>.</p> <p><strong>Examples</strong></p> <ol> <li>An if-then-fi command. <pre> x=4 y=9 if test $x -lt $y then echo $x is less than $y fi </pre> </li> <li>An if-then-else-fi command. <pre> x=10 y=9 if test $x -lt $y then echo echo $x is less than $y else echo echo $x is greater than or equal to $y fi </pre> </li> <li>An if-then-elif-else-fi command. <pre> x=4 y=4 if test $x -lt $y then echo echo $x is less than $y elif test $x -eq $y then echo $x is equal to $y else echo $x is greater than or equal to $y fi </pre> </li> </ol> </body> </html>