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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 16] 16.3 Reordering ls Listings </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="1998-08-04T21:37:37Z"><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="ch16_01.htm"TITLE="16. Where Did I Put That?"><LINKREL="prev"HREF="ch16_02.htm"TITLE="16.2 Finding Oldest or Newest Files with ls -t and ls -u "><LINKREL="next"HREF="ch16_04.htm"TITLE="16.4 List All Subdirectories with ls -R "></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="ch16_02.htm"TITLE="16.2 Finding Oldest or Newest Files with ls -t and ls -u "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 16.2 Finding Oldest or Newest Files with ls -t and ls -u "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 16<BR>Where Did I Put That?</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch16_04.htm"TITLE="16.4 List All Subdirectories with ls -R "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 16.4 List All Subdirectories with ls -R "BORDER="0"></A></TD></TR></TABLE> <HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-1571">16.3 Reordering ls Listings </A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-16767"></A>In the<SPANCLASS="link">previous tutorial (<ACLASS="linkend"HREF="ch16_02.htm"TITLE="Finding Oldest or Newest Files with ls -t and ls -u ">16.2</A>)</SPAN>,I introduced you to several different waysof sorting <EMCLASS="emphasis">ls</EM>' output, based on file time. There was oneconstant: <EMCLASS="emphasis">ls</EM> listings were always from first (most recent) tolast, moving (first) down each column and then across the page.</P><PCLASS="para">That's often not the most convenient way to look at the world.For example, if you're going to look at a directory with many, manyfiles, it might be easier to list the files <EMCLASS="emphasis">across</EM> the screenfirst, and then down. This would be particularly nice if you'reusing a pager (like <EMCLASS="emphasis">pg</EM> or<SPANCLASS="link"><EMCLASS="emphasis">more</EM> (<ACLASS="linkend"HREF="ch25_03.htm"TITLE="Using more to Page Through Files ">25.3</A>)</SPAN>)to read the listing.Then the first screenful will show the files at the top of the list.Here's an example:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">jerry@ora ~/.bin59 % <CODECLASS="userinput"><B>ls -x | pg</B></CODE>README alifile append c-w cgrepcrontab cw cx dirtop distprompterdrmm echoerr fixsubj fols inccincs maillog mhadd mhprofile pickthisrecomp reheader replf rfl rhnorhyes rmmer rn2mh rtfm saveartscandrafts showmult showpr tcx tofromunshar weather which xmhprint zfolderszloop zrefile zscan</PRE></BLOCKQUOTE></P><PCLASS="para"> This listing is "alphabetic"-not sorted by time.So <EMCLASS="emphasis">README</EM> is first in the list (uppercase comesbelow lowercase), and <EMCLASS="emphasis">alifile</EM> is next to it.<ACLASS="indexterm"NAME="AUTOID-16783"></A>The <EMCLASS="emphasis">-x</EM> flag makes the outputmulti-column.BSD doesn't have <EMCLASS="emphasis">-x</EM>.To get the same sorting order under BSD, pipe <EMCLASS="emphasis">ls</EM> outputthrough the<SPANCLASS="link"><EMCLASS="emphasis">cols</EM> (<ACLASS="linkend"HREF="ch35_16.htm"TITLE="Make Columns Automatically with cols ">35.16</A>)</SPAN>script.</P><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-16792"></A>Both BSD and System V have the <EMCLASS="emphasis">-C</EM> option; it sortsfilenames down columns instead of across.In fact, <EMCLASS="emphasis">-C</EM> is the default on BSD when you <EMCLASS="emphasis">aren't</EM>redirecting the output of <EMCLASS="emphasis">ls</EM>.If BSD <EMCLASS="emphasis">ls</EM> detects that it's writing anywhere other thana terminal, it defaults to single-column output, rather than multi-column.Under BSD, you'll need to use <EMCLASS="emphasis">-C</EM> (or another techniquelike the <EMCLASS="emphasis">cols</EM> script or <SPANCLASS="link"><EMCLASS="emphasis">pr -number</EM> (<ACLASS="linkend"HREF="ch35_17.htm"TITLE="Making Text in Columns with pr ">35.17</A>)</SPAN>)to get output in columns when you pipe <EMCLASS="emphasis">ls</EM> output.</P><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-16806"></A>The <EMCLASS="emphasis">-r</EM> option lists the files in reverse order.I find this particularly useful when I'm looking at modification times.Because <EMCLASS="emphasis">-t</EM> shows files by modification time, newest first - using<EMCLASS="emphasis">-tr</EM> shows files by modification time, oldest first:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">jerry@ora ~/.bin 61 % <CODECLASS="userinput"><B>ls -tr</B></CODE>echoerr replf zscan c-w dirtopsaveart xmhprint zrefile cx cgreprtfm distprompter reheader maillog pickthisREADME fixsubj drmm rfl rhyesappend mhadd incc showpr rhnofols rmmer tofrom zloop crontabmhprofile rn2mh scandrafts unshar weatherrecomp alifile showmult tcxincs zfolders cw which</PRE></BLOCKQUOTE></P><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-16816"></A>Adding the <EMCLASS="emphasis">-u</EM> option shows theleast recently accessed files first:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">jerry@ora ~/.bin63 % <CODECLASS="userinput"><B>ls -tur</B></CODE>README maillog which mhadd tofromalifile replf zfolders crontab tcxappend reheader zloop recomp showmultcgrep rhyes xmhprint distprompter mhprofiledirtop rhno zscan cw rmmerfixsubj showpr zrefile cx rflechoerr scandrafts drmm c-w rtfmfols saveart incc weatherincs unshar pickthis rn2mh</PRE></BLOCKQUOTE></P><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">JP</SPAN>, <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="ch16_02.htm"TITLE="16.2 Finding Oldest or Newest Files with ls -t and ls -u "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 16.2 Finding Oldest or Newest Files with ls -t and ls -u "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="ch16_04.htm"TITLE="16.4 List All Subdirectories with ls -R "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 16.4 List All Subdirectories with ls -R "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">16.2 Finding Oldest or Newest Files with ls -t and ls -u </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">16.4 List All Subdirectories with ls -R </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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