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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 40] 40.10 nextday, nextweekday: Tomorrow or Next Weekday </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="1998-08-04T21:50:39Z"><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="ch40_01.htm"TITLE="40. Delayed Execution"><LINKREL="prev"HREF="ch40_09.htm"TITLE="40.9 Checking and Removing Jobs "><LINKREL="next"HREF="ch40_11.htm"TITLE="40.11 Send Yourself Reminder Mail "></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="ch40_09.htm"TITLE="40.9 Checking and Removing Jobs "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 40.9 Checking and Removing Jobs "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 40<BR>Delayed Execution</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch40_11.htm"TITLE="40.11 Send Yourself Reminder Mail "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 40.11 Send Yourself Reminder Mail "BORDER="0"></A></TD></TR></TABLE> <HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-4430">40.10 nextday, nextweekday: Tomorrow or Next Weekday </A></H2><TABLECLASS="para.programreference"BORDER="1"><TR><THVALIGN="TOP"><ACLASS="programreference"HREF="examples/index.htm"TITLE="nextday">nextday</A><BR></TH><TDVALIGN="TOP"><ACLASS="indexterm"NAME="AUTOID-44869"></A><ACLASS="indexterm"NAME="AUTOID-44872"></A><ACLASS="indexterm"NAME="AUTOID-44874"></A>Before my UNIX systems had personal<SPANCLASS="link">crontabs (<ACLASS="linkend"HREF="ch40_12.htm"TITLE="Periodic Program Execution: The cron Facility ">40.12</A>)</SPAN>,I wanted a way to make an<SPANCLASS="link"><EMCLASS="emphasis">at</EM> job (<ACLASS="linkend"HREF="ch40_03.htm"TITLE="The at Command ">40.3</A>)</SPAN>repeat itselfthe next weekday (skipping Saturday and Sunday) or, sometimes, every day.Our <EMCLASS="emphasis">at</EM> was simple-minded and didn't understand dates like<EMCLASS="emphasis">now + 1 day</EM>.This script with two names, <EMCLASS="emphasis">nextday</EM> and <EMCLASS="emphasis">nextweekday</EM>,did the job.I called it from inside my <EMCLASS="emphasis">at</EM> job, like this:</TD></TR></TABLE><PCLASS="para"><TABLECLASS="screen.co"BORDER="1"><TR><THVALIGN="TOP"><PRECLASS="calloutlist"> <ACLASS="co"HREF="ch09_16.htm"TITLE="9.16 Command Substitution ">`...`</A> </PRE></TH><TDVALIGN="TOP"><PRECLASS="screen">% <CODECLASS="userinput"><B>cat atjob</B></CODE><CODECLASS="replaceable"><I>somecommand</I></CODE>sleep 60at 2325 `nextweekday` < atjob</PRE></TD></TR></TABLE></P><PCLASS="para">On Thursday, the result will be a command like <CODECLASS="literal">at 2325 Friday atjob</CODE>.On Friday, the command will be <CODECLASS="literal">at 2325 Monday atjob</CODE>; using<EMCLASS="emphasis">nextday</EM> instead, the result would be <CODECLASS="literal">at 2325 Saturday atjob</CODE>.</P><PCLASS="para">The <EMCLASS="emphasis">-n</EM> option returns a numeric weekday.</P><BLOCKQUOTECLASS="note"><PCLASS="para"><STRONG>NOTE:</STRONG> This script only works with some versions of <EMCLASS="emphasis">date</EM>.If your version doesn't understandformat strings like <CODECLASS="literal">+%</CODE><CODECLASS="replaceable"><I>format</I></CODE>,install the<SPANCLASS="link"><EMCLASS="emphasis">date</EM> (<ACLASS="linkend"HREF="ch51_10.htm"TITLE="The date Command ">51.10</A>)</SPAN>from the CD-ROM.</P></BLOCKQUOTE><PCLASS="para"> You can install this script from the CD-ROMor from the<SPANCLASS="link">online archive (<ACLASS="linkend"HREF="ch52_07.htm"TITLE="Other Ways to Get the Software ">52.7</A>)</SPAN>.If you get it from the archive,ask <EMCLASS="emphasis">tar</EM> to install <EMCLASS="emphasis">nextday</EM> and its other link:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>tar xvf </B></CODE><CODECLASS="replaceable"><I>archive.tar</I></CODE><CODECLASS="userinput"><B> nextday nextweekday</B></CODE>x nextday, 1564 bytes, 4 tape blocksnextweekday linked to nextday</PRE></BLOCKQUOTE></P><PCLASS="para">The script tests the name it was called with, in <CODECLASS="literal">$0</CODE>, to decidewhich command to run.</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="ch40_09.htm"TITLE="40.9 Checking and Removing Jobs "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 40.9 Checking and Removing Jobs "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="ch40_11.htm"TITLE="40.11 Send Yourself Reminder Mail "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 40.11 Send Yourself Reminder Mail "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">40.9 Checking and Removing Jobs </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">40.11 Send Yourself Reminder Mail </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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