index00.sgml

Shall高级编程

         <link linkend="functionref">function</link>, or to the script
         itself</para>
      <para><command>$0 </command>
         <link linkend="scrnameparam">Filename of the script</link></para>
      <para><command>$1 </command>
         <link linkend="posparamref1">First argument passed to script</link></para>
      <para><command>$9 </command>
         <link linkend="posparamref1">Ninth argument passed to script</link></para>
      <para><link linkend="specshvartab"><command>Table</command></link>
        of <firstterm>shell variables</firstterm></para>

<!-- End Characters and symbols -->

      <para>* * * * * *</para>

      <para><command>-a </command>
        <link linkend="compoundand">Logical AND</link>
	compound comparison test</para>
      <para><firstterm>Advanced Bash Scripting Guide</firstterm>,
         <link linkend="where_tarball">where to download</link></para>

      <para><link linkend="aliasref">Alias</link>
         <itemizedlist>
      <listitem><para><link linkend="unaliasref">Removing an
        <firstterm>alias</firstterm></link>, using
	<firstterm>unalias</firstterm></para></listitem>
          </itemizedlist></para>

      <para><link linkend="lcons1"><firstterm>And</firstterm> list</link>
         <itemizedlist>
      <listitem><para>
         <link linkend="anddefault">To supply default command-line
         argument</link></para></listitem>
         </itemizedlist></para>

      <para><link linkend="anglebrac">Angle brackets</link>,
         <firstterm>escaped</firstterm>,
	 <command>\&lt; . . . \&gt; </command>
	 word boundary in a <link linkend="regexref">Regular
	 Expression</link></para>
      <para><link linkend="anonheredoc0">Anonymous
         <firstterm>here document</firstterm></link>, using
         <command>:</command></para>

<!-- ********************** -->
      <para><link linkend="faarchiving1">Archiving</link>
         <itemizedlist>
      <listitem><para><link linkend="rpmref">rpm</link></para></listitem>
      <listitem><para><link linkend="tarref">tar</link></para></listitem>
         </itemizedlist></para>
<!-- ********************** -->
      <para><link linkend="arithexpref">Arithmetic expansion</link>
         <itemizedlist>
      <listitem><para><link linkend="arithexpvar1">
         variations of</link></para></listitem>
         </itemizedlist></para>
<!-- ********************** -->

      <para><link linkend="arops1">Arithmetic operators</link>
         <itemizedlist>
      <listitem><para><link linkend="arithopscomb">
         combination operators</link>, <firstterm>C</firstterm>-style</para>
	 <para><command> += </command>
	       <command> -= </command>
	       <command> *= </command>
               <command> /= </command>
	       <command> %= </command>
	 </para>

	 <note><para><link linkend="pluseqstr">In certain contexts</link>,
	   <command>+=</command> can also function as a <firstterm>string
	   concatenation</firstterm> operator.</para></note>

	    </listitem>
	 </itemizedlist></para>


      <para><link linkend="arrayref">Arrays</link></para>
         <itemizedlist>
	   <listitem><para><link linkend="arrayref">Bracket notation</link>
	      </para></listitem>
	   <listitem><para><link linkend="arrayappend0">Concatenating</link>,
	      <firstterm>example script</firstterm></para></listitem>
	   <listitem><para><link linkend="copyarray0">Copying</link>
	      </para></listitem>
	   <listitem><para><link
	     linkend="arraydeclare">Declaring</link></para>
           <para><varname>declare -a
		 array_name</varname></para></listitem>

	   <listitem><para><link linkend="arrayindir">Embedded
	     arrays</link></para></listitem>
	   <listitem><para><link linkend="emptyarray0">Empty
	     arrays, empty elements</link>, <firstterm>example
	     script</firstterm></para></listitem>
	   <listitem><para><link linkend="arrayindir">Indirect references</link>
	      </para></listitem>

	   <listitem>
	      <para><link linkend="arrayinit0">Initialization</link></para>
	      <para><varname>array=( element1 element2 ... elementN)</varname></para>
	      <para><link linkend="arrayassign0"><firstterm>Example
	        script</firstterm></link></para>
	      <para>Using <link linkend="arrayinitcs">command
	         substitution</link></para>
                 </listitem>

	   <listitem><para><link linkend="arrayinitcs">Loading a
	     file</link> into an array</para></listitem>
	   <listitem><para><link
	      linkend="arraymultidim">Multidimensional</link>,
              simulating</para></listitem>
	   <listitem><para><link linkend="arraynest">Nesting and
	      embedding</link></para></listitem>
	   <listitem><para><link linkend="arraynotation">Notation
	      and usage</link></para></listitem>
	   <listitem><para><link
	     linkend="arraynumelements">Number of elements in</link></para>
	     <para><varname>${#array_name[@]}</varname></para>
	     <para><varname>${#array_name[*]}</varname></para></listitem>
	   <listitem><para><link
	     linkend="arraysyntax">Operations</link></para></listitem>
           <listitem><para><link linkend="passarray">Passing
             an <firstterm>array</firstterm></link> to a
             function</para></listitem>
           <listitem><para>As <link linkend="retarray">
              <firstterm>return value</firstterm> from
	      a function</link></para></listitem>
	   <listitem><para><link
	     linkend="arrayspecialprops">Special properties</link>,
	     <firstterm>example script</firstterm></para></listitem>
	   <listitem><para><link
	     linkend="arraystringops">String operations</link>,
	     <firstterm>example script</firstterm></para></listitem>
	   <listitem><para><link
	     linkend="arrayunset"><firstterm>unset</firstterm> deletes array
	     elements</link></para></listitem>
         </itemizedlist>

      <para><link linkend="asciitable">ASCII table</link></para>

<!-- ********************** -->
      <para><link linkend="awk">awk</link> field-oriented text
         processing language
         <itemizedlist>
      <listitem><para><link linkend="awkrandomref">
         <varname>rand()</varname></link>,
	 random function</para></listitem>
      <listitem><para><link linkend="awkstringmanip2">String
        manipulation</link></para></listitem>
      <listitem><para><link linkend="exportawk">Using
	<firstterm>export</firstterm></link> to pass a variable to an
	embedded <firstterm>awk</firstterm> script</para></listitem>
         </itemizedlist></para>
<!-- ********************** -->

      <para>* * *</para>

      <para><link linkend="backticksref">Backquotes</link>,
         used in <link linkend="backquotesref">command
         substitution</link></para>
      <para><link linkend="base0">Base conversion</link>,
        <firstterm>example script</firstterm></para>

<!-- ********************** -->
      <para><link linkend="bashdef">Bash</link>
         <itemizedlist>

      <listitem><para><link linkend="bash3gotcha">Bad scripting
         practices</link></para></listitem>
      <listitem><para><link linkend="basicsrev0">Basics reviewed</link>,
        <firstterm>script example</firstterm></para></listitem>
      <listitem>
        <para><link linkend="clopts">Command-line
          options</link></para>
        <para><link
          linkend="optionstable"><command>Table</command></link></para>
	  </listitem>
      <listitem><para> <link linkend="bashcompat">Features that classic
        <firstterm>Bourne</firstterm> shell lacks</link></para></listitem>
      <listitem>
        <para><link
          linkend="internalvariables">Internal variables</link></para>
      </listitem>
      <listitem><para><link linkend="bash2ref">
        Version 2</link></para></listitem>
      <listitem><para><link linkend="bash3ref">
        Version 3</link></para></listitem>

         </itemizedlist></para>
<!-- ********************** -->


      <para><link linkend="sample-bashrc">.bashrc</link></para>
      <para><link
         linkend="bashsubshellref"><varname>$BASH_SUBSHELL</varname></link></para>
      <para><link linkend="basiccommands1">Basic commands</link>, external</para>
      <para><link linkend="batchprocref">Batch processing</link></para>

      <para><link linkend="bcref">bc</link>, calculator utility
         <itemizedlist>
      <listitem><para><link linkend="bcheredoc">In a <firstterm>here
        document</firstterm></link></para></listitem>
      <listitem><para><link linkend="bctemplate">Template</link>
        for calculating a script variable</para></listitem>
         </itemizedlist></para>

      <para><link linkend="biblio">Bibliography</link></para>
      <para><link linkend="bisonref">Bison</link> utility</para>
      <para><link linkend="bitwsops1">Bitwise operators</link></para>

      <para><link linkend="codeblockref">Blocks of code</link>
         <itemizedlist>
      <listitem>
        <para><link
          linkend="blockio">Redirection</link></para>
        <para><link
        linkend="blockio2"><firstterm>Script
        example</firstterm></link>:
	redirecting output of a a code block</para></listitem>
         </itemizedlist></para>

<!-- ********************** -->
      <para><link linkend="braceexpref">Brace expansion</link>
         <itemizedlist>
      <listitem><para><link
         linkend="braceexpref33">Extended</link>,
	   <replaceable>{a..z}</replaceable></para></listitem>
         </itemizedlist></para>
<!-- ********************** -->

      <para>Brackets, <command>[ ]</command>
         <itemizedlist>
      <listitem><para><link linkend="brackarray"><firstterm>Array</firstterm>
        element</link></para></listitem>
      <listitem><para><link linkend="bracketsref">Enclose character set
        to match</link> in a <firstterm>Regular
	Expression</firstterm></para></listitem>
      <listitem><para><link
        linkend="bracktest"><firstterm>Test</firstterm> construct</link></para>
      </listitem>
         </itemizedlist></para>

      <para>Brackets, <firstterm>curly</firstterm>, <command>{}</command>,
        used in</para>
         <itemizedlist>
      <listitem><para><link linkend="codeblockref">Code
        block</link></para></listitem>
      <listitem><para><link linkend="curlybracketsref">
         <firstterm>find</firstterm></link></para></listitem>
      <listitem><para><link linkend="escpcb"><firstterm>Extended Regular
	 Expressions</firstterm></link></para></listitem>
      <listitem><para><link linkend="bracketnotation"><firstterm>Positional
        parameters</firstterm></link></para></listitem>
      <listitem><para><link
      linkend="xargscurlyref"><firstterm>xargs</firstterm></link></para></listitem>
         </itemizedlist>

<!-- ********************** -->

      <para><link linkend="brkcont1">break</link>
         <firstterm>loop</firstterm> control command
	    <itemizedlist>
      <listitem><para><link linkend="breakparam">Parameter</link>
         (optional)</para></listitem>
	    </itemizedlist></para>

      <para><link linkend="builtinref">Builtins</link> in
         <firstterm>Bash</firstterm>
	    <itemizedlist>
      <listitem><para><link linkend="bltinfrk">Do not fork a subprocess</link>
         </para></listitem>
	    </itemizedlist></para>

      <para>* * *</para>

      <para><link linkend="caseesac1"><firstterm>case</firstterm>
         construct</link>
	    <itemizedlist>
      <listitem><para><link linkend="casecl">Command-line parameters</link>,
         handling</para></listitem>
      <listitem><para><link linkend="csglob">Globbing</link>,
         filtering strings with</para></listitem>
	    </itemizedlist></para>

      <para><link linkend="catref">cat</link>,
        con<firstterm>cat</firstterm>entate file(s)
	    <itemizedlist>
      <listitem><para><link linkend="catabuse">Abuse of</link></para></listitem>
      <listitem><para><link linkend="catscriptref"><firstterm>cat</firstterm>
         scripts</link></para></listitem>
      <listitem><para><link linkend="catlesseff">Less efficient than
        redirecting <filename>stdin</filename></link></para></listitem>
      <listitem><para><link linkend="readpiperef">Piping the output
        of</link>, to a <link linkend="readref">read</link></para></listitem>
      <listitem><para><link linkend="catuses">Uses of</link></para></listitem>
	    </itemizedlist></para>


      <para><link linkend="childref">Child processes</link></para>
      <para><link linkend="nullref">Colon</link>, <command>: </command>,
         equivalent to the <link linkend="trueref">true</link> Bash
         builtin</para>

      <para><link linkend="colorizingref">Colorizing scripts</link>
	    <itemizedlist>
         <listitem><para><link
	   linkend="coloriztable"><command>Table</command></link> of
	   color escape sequences</para></listitem>
         <listitem><para><link
	   linkend="coloriztempl">Template</link>,
	   colored text on colored background</para></listitem>
	    </itemizedlist></para>

      <para><link linkend="commaop">Comma operator</link>,
         linking commands or operations</para>

      <para><link linkend="bash-options">Command-line options</link></para>

      <para><link linkend="commandsubref">Command substitution</link>
         <itemizedlist>
      <listitem>
        <para>
         <link linkend="csparens"><command>$( ... )</command></link>,
	   preferred notation</para>
      </listitem>
       <listitem><para><link
         linkend="backquotesref"><firstterm>Backquotes</firstterm></link></para></listitem>
       <listitem><para><link linkend="cstoolset">Extending the
         <firstterm>Bash</firstterm> toolset</link></para></listitem>
       <listitem><para><link linkend="cssubsh">Invokes a
         <firstterm>subshell</firstterm></link></para></listitem>
       <listitem><para><link linkend="csnest">Nesting</link></para></listitem>
       <listitem><para><link linkend="cstrnl">Removes trailing newlines</link>
         </para></listitem>
       <listitem><para><link linkend="csvl">Setting variable from loop output</link>