271 lines
4.0 KiB
HTML
271 lines
4.0 KiB
HTML
|
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
|
|||
|
|
<HTML
|
|||
|
|
><HEAD
|
|||
|
|
><TITLE
|
|||
|
|
>Performing more than one command</TITLE
|
|||
|
|
><META
|
|||
|
|
NAME="GENERATOR"
|
|||
|
|
CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
|
|||
|
|
REL="HOME"
|
|||
|
|
TITLE="GNU/Linux Command-Line Tools Summary"
|
|||
|
|
HREF="index.html"><LINK
|
|||
|
|
REL="UP"
|
|||
|
|
TITLE="Directing Input/Output"
|
|||
|
|
HREF="directing-input-ouput.html"><LINK
|
|||
|
|
REL="PREVIOUS"
|
|||
|
|
TITLE="Command Substitution"
|
|||
|
|
HREF="command-substitution.html"><LINK
|
|||
|
|
REL="NEXT"
|
|||
|
|
TITLE="Working with the file-system"
|
|||
|
|
HREF="working-with-the-file-system.html"></HEAD
|
|||
|
|
><BODY
|
|||
|
|
CLASS="SECT1"
|
|||
|
|
BGCOLOR="#FFFFFF"
|
|||
|
|
TEXT="#000000"
|
|||
|
|
LINK="#0000FF"
|
|||
|
|
VLINK="#840084"
|
|||
|
|
ALINK="#0000FF"
|
|||
|
|
><DIV
|
|||
|
|
CLASS="NAVHEADER"
|
|||
|
|
><TABLE
|
|||
|
|
SUMMARY="Header navigation table"
|
|||
|
|
WIDTH="100%"
|
|||
|
|
BORDER="0"
|
|||
|
|
CELLPADDING="0"
|
|||
|
|
CELLSPACING="0"
|
|||
|
|
><TR
|
|||
|
|
><TH
|
|||
|
|
COLSPAN="3"
|
|||
|
|
ALIGN="center"
|
|||
|
|
>GNU/Linux Command-Line Tools Summary</TH
|
|||
|
|
></TR
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
WIDTH="10%"
|
|||
|
|
ALIGN="left"
|
|||
|
|
VALIGN="bottom"
|
|||
|
|
><A
|
|||
|
|
HREF="command-substitution.html"
|
|||
|
|
ACCESSKEY="P"
|
|||
|
|
>Prev</A
|
|||
|
|
></TD
|
|||
|
|
><TD
|
|||
|
|
WIDTH="80%"
|
|||
|
|
ALIGN="center"
|
|||
|
|
VALIGN="bottom"
|
|||
|
|
>Chapter 6. Directing Input/Output</TD
|
|||
|
|
><TD
|
|||
|
|
WIDTH="10%"
|
|||
|
|
ALIGN="right"
|
|||
|
|
VALIGN="bottom"
|
|||
|
|
><A
|
|||
|
|
HREF="working-with-the-file-system.html"
|
|||
|
|
ACCESSKEY="N"
|
|||
|
|
>Next</A
|
|||
|
|
></TD
|
|||
|
|
></TR
|
|||
|
|
></TABLE
|
|||
|
|
><HR
|
|||
|
|
ALIGN="LEFT"
|
|||
|
|
WIDTH="100%"></DIV
|
|||
|
|
><DIV
|
|||
|
|
CLASS="SECT1"
|
|||
|
|
><H1
|
|||
|
|
CLASS="SECT1"
|
|||
|
|
><A
|
|||
|
|
NAME="PERFORMING-MORE-THAN-ONE-COMMAND"
|
|||
|
|
></A
|
|||
|
|
>6.4. Performing more than one command</H1
|
|||
|
|
><P
|
|||
|
|
></P
|
|||
|
|
><DIV
|
|||
|
|
CLASS="VARIABLELIST"
|
|||
|
|
><DL
|
|||
|
|
><DT
|
|||
|
|
>Executing<6E>the<68>second<6E>command<6E>only<6C>if<69>the<68>first<73>is<69>successful<A
|
|||
|
|
NAME="EXECUTE-COMMAND-2-IF-1-WORKS"
|
|||
|
|
></A
|
|||
|
|
></DT
|
|||
|
|
><DD
|
|||
|
|
><P
|
|||
|
|
><3E></P
|
|||
|
|
><P
|
|||
|
|
>To do this you would type:</P
|
|||
|
|
><TABLE
|
|||
|
|
BORDER="1"
|
|||
|
|
BGCOLOR="#E0E0E0"
|
|||
|
|
WIDTH="90%"
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
><FONT
|
|||
|
|
COLOR="#000000"
|
|||
|
|
><PRE
|
|||
|
|
CLASS="SCREEN"
|
|||
|
|
>command1 && command2</PRE
|
|||
|
|
></FONT
|
|||
|
|
></TD
|
|||
|
|
></TR
|
|||
|
|
></TABLE
|
|||
|
|
><P
|
|||
|
|
>command2 will be executed if command1 successfully completes (if command1 fails command2 won't be run). This is called a logical AND.</P
|
|||
|
|
></DD
|
|||
|
|
><DT
|
|||
|
|
>Executing<6E>the<68>second<6E>command<6E>only<6C>if<69>the<68>first<73>fails<A
|
|||
|
|
NAME="EXECUTE-COMMAND-2-IF-1-FAILS"
|
|||
|
|
></A
|
|||
|
|
></DT
|
|||
|
|
><DD
|
|||
|
|
><P
|
|||
|
|
><3E></P
|
|||
|
|
><P
|
|||
|
|
>To do this you would type:</P
|
|||
|
|
><TABLE
|
|||
|
|
BORDER="1"
|
|||
|
|
BGCOLOR="#E0E0E0"
|
|||
|
|
WIDTH="90%"
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
><FONT
|
|||
|
|
COLOR="#000000"
|
|||
|
|
><PRE
|
|||
|
|
CLASS="SCREEN"
|
|||
|
|
>command1 || command2</PRE
|
|||
|
|
></FONT
|
|||
|
|
></TD
|
|||
|
|
></TR
|
|||
|
|
></TABLE
|
|||
|
|
><P
|
|||
|
|
>command2 will be executed if command1 does not successfully complete (if command1 is successful command2 won't be run). This is called a logical OR.</P
|
|||
|
|
></DD
|
|||
|
|
><DT
|
|||
|
|
>Executing<6E>commands<64>sequentially<A
|
|||
|
|
NAME="EXECUTING-COMMANDS-SEQUENTIALLY"
|
|||
|
|
></A
|
|||
|
|
></DT
|
|||
|
|
><DD
|
|||
|
|
><P
|
|||
|
|
><3E></P
|
|||
|
|
><P
|
|||
|
|
>To execute commands sequentially regardless of the success/failure of the previous you simply type:</P
|
|||
|
|
><TABLE
|
|||
|
|
BORDER="1"
|
|||
|
|
BGCOLOR="#E0E0E0"
|
|||
|
|
WIDTH="90%"
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
><FONT
|
|||
|
|
COLOR="#000000"
|
|||
|
|
><PRE
|
|||
|
|
CLASS="SCREEN"
|
|||
|
|
>command1; command2</PRE
|
|||
|
|
></FONT
|
|||
|
|
></TD
|
|||
|
|
></TR
|
|||
|
|
></TABLE
|
|||
|
|
><P
|
|||
|
|
>command2 will execute once command1 has completed.</P
|
|||
|
|
><DIV
|
|||
|
|
CLASS="TIP"
|
|||
|
|
><P
|
|||
|
|
></P
|
|||
|
|
><TABLE
|
|||
|
|
CLASS="TIP"
|
|||
|
|
WIDTH="90%"
|
|||
|
|
BORDER="0"
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
WIDTH="25"
|
|||
|
|
ALIGN="CENTER"
|
|||
|
|
VALIGN="TOP"
|
|||
|
|
><IMG
|
|||
|
|
SRC="../images/tip.gif"
|
|||
|
|
HSPACE="5"
|
|||
|
|
ALT="Tip"></TD
|
|||
|
|
><TH
|
|||
|
|
ALIGN="LEFT"
|
|||
|
|
VALIGN="CENTER"
|
|||
|
|
><B
|
|||
|
|
>More than two commands</B
|
|||
|
|
></TH
|
|||
|
|
></TR
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
> </TD
|
|||
|
|
><TD
|
|||
|
|
ALIGN="LEFT"
|
|||
|
|
VALIGN="TOP"
|
|||
|
|
><P
|
|||
|
|
>You can continue to use ';' (semicolon) characters to do more and more commands on the one line.</P
|
|||
|
|
></TD
|
|||
|
|
></TR
|
|||
|
|
></TABLE
|
|||
|
|
></DIV
|
|||
|
|
></DD
|
|||
|
|
></DL
|
|||
|
|
></DIV
|
|||
|
|
></DIV
|
|||
|
|
><DIV
|
|||
|
|
CLASS="NAVFOOTER"
|
|||
|
|
><HR
|
|||
|
|
ALIGN="LEFT"
|
|||
|
|
WIDTH="100%"><TABLE
|
|||
|
|
SUMMARY="Footer navigation table"
|
|||
|
|
WIDTH="100%"
|
|||
|
|
BORDER="0"
|
|||
|
|
CELLPADDING="0"
|
|||
|
|
CELLSPACING="0"
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
WIDTH="33%"
|
|||
|
|
ALIGN="left"
|
|||
|
|
VALIGN="top"
|
|||
|
|
><A
|
|||
|
|
HREF="command-substitution.html"
|
|||
|
|
ACCESSKEY="P"
|
|||
|
|
>Prev</A
|
|||
|
|
></TD
|
|||
|
|
><TD
|
|||
|
|
WIDTH="34%"
|
|||
|
|
ALIGN="center"
|
|||
|
|
VALIGN="top"
|
|||
|
|
><A
|
|||
|
|
HREF="index.html"
|
|||
|
|
ACCESSKEY="H"
|
|||
|
|
>Home</A
|
|||
|
|
></TD
|
|||
|
|
><TD
|
|||
|
|
WIDTH="33%"
|
|||
|
|
ALIGN="right"
|
|||
|
|
VALIGN="top"
|
|||
|
|
><A
|
|||
|
|
HREF="working-with-the-file-system.html"
|
|||
|
|
ACCESSKEY="N"
|
|||
|
|
>Next</A
|
|||
|
|
></TD
|
|||
|
|
></TR
|
|||
|
|
><TR
|
|||
|
|
><TD
|
|||
|
|
WIDTH="33%"
|
|||
|
|
ALIGN="left"
|
|||
|
|
VALIGN="top"
|
|||
|
|
>Command Substitution</TD
|
|||
|
|
><TD
|
|||
|
|
WIDTH="34%"
|
|||
|
|
ALIGN="center"
|
|||
|
|
VALIGN="top"
|
|||
|
|
><A
|
|||
|
|
HREF="directing-input-ouput.html"
|
|||
|
|
ACCESSKEY="U"
|
|||
|
|
>Up</A
|
|||
|
|
></TD
|
|||
|
|
><TD
|
|||
|
|
WIDTH="33%"
|
|||
|
|
ALIGN="right"
|
|||
|
|
VALIGN="top"
|
|||
|
|
>Working with the file-system</TD
|
|||
|
|
></TR
|
|||
|
|
></TABLE
|
|||
|
|
></DIV
|
|||
|
|
></BODY
|
|||
|
|
></HTML
|
|||
|
|
>
|