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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 32] 32.8 Rational Searches </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="1998-08-04T21:46:37Z"><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="ch32_01.htm"TITLE="32. GNU Emacs"><LINKREL="prev"HREF="ch32_07.htm"TITLE="32.7 Mike's Favorite Time Savers "><LINKREL="next"HREF="ch32_09.htm"TITLE="32.9 Unset PWD Before Using Emacs "></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="ch32_07.htm"TITLE="32.7 Mike's Favorite Time Savers "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 32.7 Mike's Favorite Time Savers "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 32<BR>GNU Emacs</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch32_09.htm"TITLE="32.9 Unset PWD Before Using Emacs "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 32.9 Unset PWD Before Using Emacs "BORDER="0"></A></TD></TR></TABLE> <HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-5546">32.8 Rational Searches </A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-36025"></A><ACLASS="indexterm"NAME="AUTOID-36028"></A>Emacs has, oh, a hundred or so different search commands. (Well,really, the number's probably more like 32, but who's counting?)There are searches of absolutely every flavor you could ever imagine:incremental searches, word searches,[3]regular expression searches, and so on.</P><BLOCKQUOTECLASS="footnote"><PCLASS="para">[3] These are especially nice because they can search for phrases thatcross linebreaks; most searches assume that all the text you wantwill all be on the same line. However, you can only search for wholewords, and if you use<SPANCLASS="link"><EMCLASS="emphasis">troff</EM> or TeX (<ACLASS="linkend"HREF="ch43_12.htm"TITLE="Typesetting Overview ">43.12</A>)</SPAN>,Emacs may be confused byyour "markup."</P></BLOCKQUOTE><PCLASS="para">However, when it comes to your plain, old garden-variety search,Emacs is strangely deficient. There is a simple search that justlooks for some arbitrary sequence of characters; but it's rather wellhidden. And it lacks one very important feature: you can't search for the same string repeatedly.That is, you can't say "OK, you found the right sequence of letters;give me the next occurrence"; you have to retype your search stringevery time.</P><TABLECLASS="para.programreference"BORDER="1"><TR><THVALIGN="TOP"><ACLASS="programreference"HREF="examples/index.htm"TITLE="search.el">search.el</A><BR></TH><TDVALIGN="TOP"><ACLASS="indexterm"NAME="AUTOID-36037"></A>I thought this was an incredible pain until a friend of mine wrotea special search command. It's in the file <EMCLASS="emphasis">search.el</EM>.Just stick this into your <SPANCLASS="link">directory for Emacs hacks (<ACLASS="linkend"HREF="ch04_04.htm"TITLE="Directories for Emacs Hacks ">4.4</A>)</SPAN>,and add something like the followingto your <EMCLASS="emphasis">.emacs</EM> file:</TD></TR></TABLE><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">;; real searches, courtesy of Chris Genly;; substitute your own Emacs hack directory for /home/los/mikel/emacs (load-file "/home/los/mikel/emacs/search.el")</PRE></BLOCKQUOTE></P><PCLASS="para">Now you can type CTRL-s to search forward and CTRL-r tosearch back. Emacs will prompt you for a search string and startsearching when you press RETURN. Typing another CTRL-s orCTRL-r repeats your previous search. When you try this, you'll see one other useful feature: unlike the other Emacs searches, this kind of search displays the "default" (i.e., most recent) search string in the mini-buffer. It's exactly the kind of search I want.</P><PCLASS="para">It's conceivable that you'll occasionally want incremental searches. You'll have to "rebind" them in order to use them conveniently. Here are the key bindings that I use:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">;; rebind incremental search as ESC-s and ESC-r (define-key global-map "\M-s" 'isearch-forward) (define-key global-map "\M-r" 'isearch-backward) ;; have to rebind ESC s separately for text-mode. It's normally ;; bound to 'center-line'. (define-key text-mode-map "\M-s" 'isearch-forward)</PRE></BLOCKQUOTE></P><PCLASS="para">That is: <CODECLASS="literal">ESC s</CODE> and <CODECLASS="literal">ESC r</CODE> now give you forward and reverse incremental searches. And once you've started an incremental search, CTRL-s and CTRL-r still repeat the previous incremental search, just like they're supposed to.</P><PCLASS="para">Of course, now you'll have to rebind the "center-line" command if you're fond of it. In my opinion, it's not worth the trouble. The game of "musical key-bindings" stops here.</P><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">ML</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="ch32_07.htm"TITLE="32.7 Mike's Favorite Time Savers "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 32.7 Mike's Favorite Time Savers "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="ch32_09.htm"TITLE="32.9 Unset PWD Before Using Emacs "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 32.9 Unset PWD Before Using Emacs "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">32.7 Mike's Favorite Time Savers </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">32.9 Unset PWD Before Using Emacs </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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