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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 2] 2.11 Faster ksh and bash Startup with $- Test </TITLE><METANAME="DC.title"CONTENT="UNIX Power Tools"><METANAME="DC.creator"CONTENT="Jerry Peek, Tim O'Reilly & Mike Loukides"><METANAME="DC.publisher"CONTENT="O'Reilly & Associates, Inc."><METANAME="DC.date"CONTENT="1998-08-04T21:32:11Z"><METANAME="DC.type"CONTENT="Text.Monograph"><METANAME="DC.format"CONTENT="text/html"SCHEME="MIME"><METANAME="DC.source"CONTENT="1-56592-260-3"SCHEME="ISBN"><METANAME="DC.language"CONTENT="en-US"><METANAME="generator"CONTENT="Jade 1.1/O'Reilly DocBook 3.0 to HTML 4.0"><LINKREV="made"HREF="mailto:online-books@oreilly.com"TITLE="Online Books Comments"><LINKREL="up"HREF="ch02_01.htm"TITLE="2. Logging In"><LINKREL="prev"HREF="ch02_10.htm"TITLE="2.10 Gotchas in set prompt Test "><LINKREL="next"HREF="ch02_12.htm"TITLE="2.12 Automatic Setups for Different Terminals "></HEAD><BODYBGCOLOR="#FFFFFF"TEXT="#000000"><DIVCLASS="htmlnav"><H1><IMGSRC="gifs/smbanner.gif"ALT="UNIX Power Tools"USEMAP="#srchmap"BORDER="0"></H1><MAPNAME="srchmap"><AREASHAPE="RECT"COORDS="0,0,466,58"HREF="index.htm"ALT="UNIX Power Tools"><AREASHAPE="RECT"COORDS="467,0,514,18"HREF="jobjects/fsearch.htm"ALT="Search this book"></MAP><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch02_10.htm"TITLE="2.10 Gotchas in set prompt Test "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 2.10 Gotchas in set prompt Test "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 2<BR>Logging In</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch02_12.htm"TITLE="2.12 Automatic Setups for Different Terminals "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 2.12 Automatic Setups for Different Terminals "BORDER="0"></A></TD></TR></TABLE> <HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-0489">2.11 Faster ksh and bash Startup with $- Test </A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-3409"></A><ACLASS="indexterm"NAME="AUTOID-3412"></A><ACLASS="indexterm"NAME="AUTOID-3415"></A><ACLASS="indexterm"NAME="AUTOID-3417"></A><ACLASS="indexterm"NAME="AUTOID-3420"></A>Do you use the Korn shell - and does your account have an<SPANCLASS="link">"<EMCLASS="emphasis">ENV</EM> file" (<ACLASS="linkend"HREF="ch02_02.htm"TITLE="Shell Setup Files-Which, Where, and Why ">2.2</A>)</SPAN>(a startup file named in the <EMCLASS="emphasis">ENV</EM> environment variable)?<EMCLASS="emphasis">bash</EM> users, you probably have setup files like <EMCLASS="emphasis">.bashrc</EM> or<EMCLASS="emphasis">.bash_login</EM>.You might have the same<SPANCLASS="link">problem (<ACLASS="linkend"HREF="ch02_09.htm"TITLE="Speeding Up Your C Shell with set prompt Test ">2.9</A>)</SPAN>that C shell users have with <EMCLASS="emphasis">.cshrc</EM>:noninteractive shells read aliases and other lines that you wantto be read only by interactive shells.Speed up your file by adding a test like this:</P><PCLASS="para"><TABLECLASS="screen.co"BORDER="1"><TR><THVALIGN="TOP"><PRECLASS="calloutlist"><ACLASS="co"HREF="ch44_06.htm"TITLE="44.6 Pattern Matching in case Statements ">case</A> </PRE></TH><TDVALIGN="TOP"><PRECLASS="screen">case $- in *i*);; *) return 0;;esac# COMMANDS BELOW THIS LINE WILL ONLY BE RUN BY INTERACTIVE SHELLS: ...</PRE></TD></TR></TABLE></P><PCLASS="para">The test checks to see if the shell's <EMCLASS="emphasis">-i</EM> option is set.If it isn't, the <CODECLASS="literal">return</CODE> <CODECLASS="literal">0</CODE> quits the file.</P><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">JP</SPAN></P></DIV></DIV><DIVCLASS="htmlnav"><P></P><HRALIGN="LEFT"WIDTH="515"TITLE="footer"><TABLEWIDTH="515"BORDER="0"CELLSPACING="0"CELLPADDING="0"><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch02_10.htm"TITLE="2.10 Gotchas in set prompt Test "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 2.10 Gotchas in set prompt Test "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><ACLASS="book"HREF="index.htm"TITLE="UNIX Power Tools"><IMGSRC="gifs/txthome.gif"SRC="gifs/txthome.gif"ALT="UNIX Power Tools"BORDER="0"></A></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch02_12.htm"TITLE="2.12 Automatic Setups for Different Terminals "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 2.12 Automatic Setups for Different Terminals "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">2.10 Gotchas in set prompt Test </TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><ACLASS="index"HREF="index/idx_0.htm"TITLE="Book Index"><IMGSRC="gifs/index.gif"SRC="gifs/index.gif"ALT="Book Index"BORDER="0"></A></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172">2.12 Automatic Setups for Different Terminals </TD></TR></TABLE><HRALIGN="LEFT"WIDTH="515"TITLE="footer"><IMGSRC="gifs/smnavbar.gif"SRC="gifs/smnavbar.gif"USEMAP="#map"BORDER="0"ALT="The UNIX CD Bookshelf Navigation"><MAPNAME="map"><AREASHAPE="RECT"COORDS="0,0,73,21"HREF="../index.htm"ALT="The UNIX CD Bookshelf"><AREASHAPE="RECT"COORDS="74,0,163,21"HREF="index.htm"ALT="UNIX Power Tools"><AREASHAPE="RECT"COORDS="164,0,257,21"HREF="../unixnut/index.htm"ALT="UNIX in a Nutshell"><AREASHAPE="RECT"COORDS="258,0,321,21"HREF="../vi/index.htm"ALT="Learning the vi Editor"><AREASHAPE="RECT"COORDS="322,0,378,21"HREF="../sedawk/index.htm"ALT="sed & awk"><AREASHAPE="RECT"COORDS="379,0,438,21"HREF="../ksh/index.htm"ALT="Learning the Korn Shell"><AREASHAPE="RECT"COORDS="439,0,514,21"HREF="../lrnunix/index.htm"ALT="Learning the UNIX Operating System"></MAP></DIV></BODY></HTML>⌨️ 快捷键说明
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