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

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<title>Command language</title>
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<h2>Command language</h2>
<p><strong>qsh</strong> is a program that:</p>
<ul>
<li>reads input from either a file or a terminal</li>
<li>breaks the input into tokens</li>
<li>parses the input into simple and compound commands</li>
<li>performs various expansions on each command</li>
<li>performs redirection of input and output</li>
<li>runs the commands</li>
<li>optionally waits for the commands to complete</li>
</ul>
<p><strong>qsh</strong> implements a command language that has flow
control constructs, variables, and functions. The interpretative
language is common to both interactive and non-interactive use
(shell scripts). So the same commands that are entered at an
interactive command line can also be put in a file and the file can
be run directly by <strong>qsh</strong>.</p>
<p>For more information about particular features of <strong>
qsh</strong>, see the following topics:</p>
<blockquote>
<p><strong><a href="quoting.htm">Quoting</a></strong><br>
Select this link to view information about quoting, including the escape
character, literal quotes, and grouping quotes.</p>
<p><strong><a href="params.htm">Parameters</a></strong><br>
Select this link to view information about parameters, including positional
parameters and special parameters.</p>
<p><strong><a href="variable.htm">Variables</a></strong><br>
Select this link to view information about variables, including the variables set by
and variables used by <strong>qsh</strong>.</p>
<p><strong><a href="wordexp.htm">Word expansions</a></strong><br>
Select this link to view information about word expansions, including tilde expansion,
parameter expansion, command substitution, arithmetic expansion, field splitting, path name
expansion, and quote removal.</p>
<p><strong><a href="redirect.htm">Redirection</a></strong><br>
Select this link to view information about input and output redirections.</p>
<p><strong><a href="simpcmds.htm">Simple commands</a></strong><br>
Select this link to view information about running simple commands.</p>
<p><strong><a href="pipeline.htm">Pipelines</a></strong><br>
Select this link to view information about running multiple commands in a pipeline.</p>
<p><strong><a href="lists.htm">Lists</a></strong><br>
Select this link to view information about running multiple commands in a list.</p>
<p><strong><a href="cmpdcmds.htm">Compound commands</a></strong><br>
Select this link to view information about compound commands, including grouping
commands, conditional commands, loop commands, and functions.
</p></blockquote>
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