569 lines
6.9 KiB
HTML
569 lines
6.9 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Common features</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="Introduction to Linux"
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TITLE="Shell Features"
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TITLE="Shell Features"
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TITLE="Differing features"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>Introduction to Linux: </TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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><A
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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>Appendix C. Shell Features</TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="sect1"
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><H1
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CLASS="sect1"
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><A
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NAME="AEN12120"
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></A
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>C.1. Common features</H1
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><P
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> The following features are standard in every shell. Note that the stop, suspend,
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jobs, bg and fg commands are only available on systems that support job control.</P
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><DIV
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CLASS="table"
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><A
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NAME="AEN12123"
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></A
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><P
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><B
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>Table C-1. Common Shell Features</B
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></P
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><TABLE
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BORDER="1"
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CLASS="CALSTABLE"
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><THEAD
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><TR
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><TH
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Command</TH
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><TH
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Meaning</TH
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></TR
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></THEAD
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><TBODY
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>></TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Redirect output</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>>></TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Append to file</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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><</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Redirect input</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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><<</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>"Here" document (redirect input)</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>|</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Pipe output</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>&</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Run process in background.</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>;</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Separate commands on same line</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>*</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Match any character(s) in filename</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>?</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Match single character in filename</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>[ ]</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Match any characters enclosed</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>( )</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Execute in subshell</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>` `</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Substitute output of enclosed command</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>" "</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Partial quote (allows variable and command expansion)</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>' '</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Full quote (no expansion)</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>\</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Quote following character</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>$var</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Use value for variable</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>$$</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Process id</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>$0</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Command name</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>$n</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>nth argument (n from 0 to 9)</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>$*</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>All arguments as a simple word</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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> <TT
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CLASS="literal"
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>#</TT
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>
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</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Begin comment</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>bg</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Background execution</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>break</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Break from loop statements</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>cd</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Change directories</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>continue</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Resume a program loop</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>echo</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Display output</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>eval</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Evaluate arguments</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>exec</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Execute a new shell</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>fg</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Foreground execution</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>jobs</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Show active jobs</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>kill</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Terminate running jobs</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>newgrp</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Change to a new group</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>shift</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Shift positional parameters</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>stop</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Suspend a background job</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>suspend</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Suspend a foreground job</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>time</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Time a command</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>umask</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Set or list file permissions</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>unset</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Erase variable or function definitions</TD
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></TR
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><TR
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>wait</TD
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><TD
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ALIGN="LEFT"
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VALIGN="MIDDLE"
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>Wait for a background job to finish</TD
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></TR
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></TBODY
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></TABLE
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></DIV
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CLASS="NAVFOOTER"
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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HREF="app3.html"
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>Prev</A
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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ACCESSKEY="H"
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>Home</A
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>Next</A
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Shell Features</TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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HREF="app3.html"
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>Up</A
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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>Differing features</TD
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