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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 35] 35.14 Cutting Columns or Fields with cut </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="1998-08-04T21:48:15Z"><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="ch35_01.htm"TITLE="35. You Can't Quite Call This Editing"><LINKREL="prev"HREF="ch35_13.htm"TITLE="35.13 Other Conversions with dd "><LINKREL="next"HREF="ch35_15.htm"TITLE="35.15 Cutting Columns with colrm "></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="ch35_13.htm"TITLE="35.13 Other Conversions with dd "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 35.13 Other Conversions with dd "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 35<BR>You Can't Quite Call This Editing</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch35_15.htm"TITLE="35.15 Cutting Columns with colrm "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 35.15 Cutting Columns with colrm "BORDER="0"></A></TD></TR></TABLE> <HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-2930">35.14 Cutting Columns or Fields with cut </A></H2><TABLECLASS="para.programreference"BORDER="1"><TR><THVALIGN="TOP"><ACLASS="programreference"HREF="examples/index.htm"TITLE="cut+paste">cut+paste</A><BR></TH><TDVALIGN="TOP"><ACLASS="indexterm"NAME="UPT-ART-2930-IX-COLUMNS-FORMATTING"></A><ACLASS="indexterm"NAME="UPT-ART-2930-IX-TEXT-PROCESSING-FORMATTING-COLUMNS"></A><ACLASS="indexterm"NAME="AUTOID-40862"></A><ACLASS="indexterm"NAME="AUTOID-40865"></A>System V includes a nifty command called <EMCLASS="emphasis">cut</EM> that lets youselect a list of columns or fields from one or more files.We've also included a public-domain version on the disc, for those ofyou whose systems do without.</TD></TR></TABLE><PCLASS="para">You must specify either the <EMCLASS="emphasis">-c</EM> option to cut by column or<EMCLASS="emphasis">-f</EM> to cut by fields.(Fields are separated by tabsunless you specify a different field separatorwith <EMCLASS="emphasis">-d</EM>.Use<SPANCLASS="link">quotes (<ACLASS="linkend"HREF="ch08_14.htm"TITLE="Bourne Shell Quoting ">8.14</A>)</SPAN>if you want a space or other specialcharacter as the delimiter.)</P><PCLASS="para">The column(s) or field(s) to cut must follow the option immediately,without any space.Use a comma between separate valuesand a hyphen to specify a range (e.g., <CODECLASS="literal">1-10</CODE>, <CODECLASS="literal">15</CODE>, <CODECLASS="literal">20</CODE>, or <CODECLASS="literal">50-</CODE>).<ACLASS="indexterm"NAME="AUTOID-40879"></A></P><PCLASS="para"><EMCLASS="emphasis">cut</EM> is incredibly handy.Here are some examples:</P><ULCLASS="itemizedlist"><LICLASS="listitem"><PCLASS="para">Find out who is logged in, but list only login names:</P><PCLASS="para"><TABLECLASS="screen.co"BORDER="1"><TR><THVALIGN="TOP"><PRECLASS="calloutlist"><ACLASS="co"HREF="ch51_04.htm"TITLE="51.4 Who's On? ">who</A> </PRE></TH><TDVALIGN="TOP"><PRECLASS="screen">% <CODECLASS="userinput"><B>who | cut -d" " -f1</B></CODE></PRE></TD></TR></TABLE></P><PCLASS="para"></P></LI><LICLASS="listitem"><PCLASS="para">Extract usernames and real names from<SPANCLASS="link"><EMCLASS="emphasis">/etc/passwd</EM> (<ACLASS="linkend"HREF="ch36_03.htm"TITLE="Changing the Field Delimiter ">36.3</A>)</SPAN>:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>cut -d: -f1,5 /etc/passwd</B></CODE></PRE></BLOCKQUOTE></P><PCLASS="para"></P></LI><LICLASS="listitem"><PCLASS="para">Cut characters in the fourth column of <EMCLASS="emphasis">file</EM>, and paste themback as the first column in the same file:</P><PCLASS="para"><TABLECLASS="screen.co"BORDER="1"><TR><THVALIGN="TOP"><PRECLASS="calloutlist"><ACLASS="co"HREF="ch35_18.htm"TITLE="35.18 Pasting Things in Columns ">paste</A> </PRE></TH><TDVALIGN="TOP"><PRECLASS="screen">% <CODECLASS="userinput"><B>cut -c4 <CODECLASS="replaceable"><I>file </I></CODE>| paste - <CODECLASS="replaceable"><I>file</I></CODE></B></CODE></PRE></TD></TR></TABLE></P></LI></UL><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">TOR</SPAN>, <SPANCLASS="authorinitials">DG</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="ch35_13.htm"TITLE="35.13 Other Conversions with dd "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 35.13 Other Conversions with dd "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="ch35_15.htm"TITLE="35.15 Cutting Columns with colrm "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 35.15 Cutting Columns with colrm "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">35.13 Other Conversions with dd </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">35.15 Cutting Columns with colrm </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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