📄 ch21_02.htm
字号:
<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 21] 21.2 A Better Place for Temporary Files: /tmp </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="1998-08-04T21:39:59Z"><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="ch21_01.htm"TITLE="21. More About Managing Files"><LINKREL="prev"HREF="ch21_01.htm"TITLE="21.1 A Grab-Bag "><LINKREL="next"HREF="ch21_03.htm"TITLE="21.3 Unique Names for Temporary Files "></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="ch21_01.htm"TITLE="21.1 A Grab-Bag "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 21.1 A Grab-Bag "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 21<BR>More About Managing Files</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch21_03.htm"TITLE="21.3 Unique Names for Temporary Files "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 21.3 Unique Names for Temporary Files "BORDER="0"></A></TD></TR></TABLE> <HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="SECT1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-6690">21.2 A Better Place for Temporary Files: /tmp </A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-22936"></A><ACLASS="indexterm"NAME="AUTOID-22940"></A>How many times have you made a little test file for something:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>grep foo bar > baz</B></CODE></PRE></BLOCKQUOTE></P><PCLASS="para">then forgotten to remove <EMCLASS="emphasis">baz</EM>-and found it, weeks later, clutteringup your directory and wasting disk space?Yeah, me too.So I decided to make my temporary files in the system temporary-filedirectory, <EMCLASS="emphasis">/tmp</EM>.</P><PCLASS="para">Everyone on the system has permission to write files there.Because there are lots of temporary files, it's good to use <SPANCLASS="link">a name that won't conflict with other people's files (<ACLASS="linkend"HREF="ch21_03.htm"TITLE="Unique Names for Temporary Files ">21.3</A>)</SPAN>.</P><PCLASS="para">If your file doesn't have<SPANCLASS="link">world permission (<ACLASS="linkend"HREF="ch22_04.htm"TITLE="Setting an Exact umask ">22.4</A>, <ACLASS="linkend"HREF="ch22_02.htm"TITLE="Tutorial on File and Directory Permissions ">22.2</A>)</SPAN>,other people on the system won't be able to read or write it.But they may be<SPANCLASS="link">able to rename or remove it (<ACLASS="linkend"HREF="ch23_10.htm"TITLE="Deletion with Prejudice: rm -f ">23.10</A>)</SPAN>unless the <EMCLASS="emphasis">/tmp</EM> directory's<SPANCLASS="link">sticky bit (<ACLASS="linkend"HREF="ch22_06.htm"TITLE="Protecting Files with the Sticky Bit ">22.6</A>)</SPAN>is set.That usually isn't a problem, but you should know that it can happen.</P><PCLASS="para">Most systems delete leftover files in <EMCLASS="emphasis">/tmp</EM> every day or so, whenthe filesystem fills up, or at least when the system is rebooted.So, don't use <EMCLASS="emphasis">/tmp</EM> for a file that you want to keep for a while.Yoursystem may have other directories for temporary files, like<SPANCLASS="link"><EMCLASS="emphasis">/usr/tmp</EM> (<ACLASS="linkend"HREF="ch21_04.htm"TITLE="Why Both /tmp and /usr/tmp? ">21.4</A>)</SPAN>,that aren't erased as often.Your system administrator should be able to tell you.</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="ch21_01.htm"TITLE="21.1 A Grab-Bag "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 21.1 A Grab-Bag "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="ch21_03.htm"TITLE="21.3 Unique Names for Temporary Files "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 21.3 Unique Names for Temporary Files "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">21.1 A Grab-Bag </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">21.3 Unique Names for Temporary Files </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
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -