ibm-information-center/dist/eclipse/plugins/i5OS.ic.rzahz_5.4.0.1/differ.htm

94 lines
3.1 KiB
HTML

<!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>Differences between Qshell and other interpreters</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>Differences with other interpreters</h2>
<p>While <strong>qsh</strong> is compatible with other standard
shell interpreters, there are several differences:</p>
<ul>
<li>There is no support for the <strong>&lt;&gt;</strong>
redirection operator.<p></li>
<li>There is no support for a command history list, the <strong>
HISTSIZE</strong> and <strong>HISTFILE</strong> variables, or the
<strong>fc</strong> (or <strong>hist</strong>) built-in utility. As
an alternative, the QSH CL command has support for command
retrieval.<p></li>
<li>There is no support for command line editing and the <strong>
EDITOR</strong> variable.<p></li>
<li>There is no support for the <strong>MAIL</strong>, <strong>
MAILCHECK</strong>, and <strong>MAILPATH</strong> variables.<p></li>
<li>There is no support for job control. There is no concept of a
foreground or background process group on i5/OS<SUP>(TM)</SUP>. This means it is
possible for multiple jobs to be reading from the terminal at the
same time. <strong>qsh</strong> does not support: <p>
<ul>
<li>The <strong>fg</strong> or <strong>bg</strong> built-in
utilities.<p></li>
<li>Using the <em>Suspend</em> key (typically &lt;ctrl&gt;z) to
send the SIGTSTP signal to the foreground process group.<p></li>
<li>Using the <em>Stop</em> key (typically &lt;ctrl&gt;s) to send
the SIGSTOP signal to the foreground process group.<p></li>
<li>Using the <em>Restart</em> key (typically &lt;ctrl&gt;q) to
send the SIGCONT signal to the foreground process group.<p></li>
<li>Using the <em>Interrupt</em> key (typically &lt;ctrl&gt;c) to
send the SIGINT signal to the foreground process group. As an
alternative, you can use SysReq 2 from an interactive shell session
to send the SIGINT signal to the shell interpreter process and any
currently running child processes.<p></li>
</ul>
<p></li>
<li>There is no support for the <em>End-of-file</em> key (typically
&lt;ctrl&gt;d). As an alternative, use a <a href=
"redirect.htm#here">here-document</a> to redirect text entered at
the command line to standard input of a utility.<p></li>
<li>
When calling a program, there is a limit to the maximum number of
parameters you can pass to the command. If the program was built for
a release before V5R3, the limit is 255 parameters. If the program was
built for V5R3 or a subsequent release, the limit is 65535 parameters.
<p></li>
<li>When using path name expansion with some case insensitive file
systems, you must use upper case characters in the pattern. For
example, to list all of the program objects in the QSHELL library
you should use this command:
<pre>
ls /qsys.lib/qshell.lib/*.PGM.
</pre>
<p></li>
</ul>
</body>
</html>