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<HTML><!--Distributed by F --><HEAD><TITLE>[Chapter 50] Help--Online Documentation, etc.</TITLE><METANAME="DC.title"CONTENT="UNIX Power Tools"><METANAME="DC.creator"CONTENT="Jerry Peek, Tim O'Reilly &amp; Mike Loukides"><METANAME="DC.publisher"CONTENT="O'Reilly &amp; Associates, Inc."><METANAME="DC.date"CONTENT="1998-08-04T21:56:48Z"><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="part09.htm"TITLE="IX. Miscellaneous "><LINKREL="prev"HREF="ch49_09.htm"TITLE="49.9 Business Graphics with ipl "><LINKREL="next"HREF="ch50_02.htm"TITLE="50.2 The apropos Command "></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="ch49_09.htm"TITLE="49.9 Business Graphics with ipl "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 49.9 Business Graphics with ipl "BORDER="0"></A></TD><TDALIGN="CENTER"VALIGN="TOP"WIDTH="171"><B><FONTFACE="ARIEL,HELVETICA,HELV,SANSERIF"SIZE="-1">Chapter 50</FONT></B></TD><TDALIGN="RIGHT"VALIGN="TOP"WIDTH="172"><ACLASS="SECT1"HREF="ch50_02.htm"TITLE="50.2 The apropos Command "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 50.2 The apropos Command "BORDER="0"></A></TD></TR></TABLE>&nbsp;<HRALIGN="LEFT"WIDTH="515"TITLE="footer"></DIV><DIVCLASS="CHAPTER"><H1CLASS="chapter"><ACLASS="title"NAME="UPT-CHP-50">50. Help--Online Documentation, etc.</A></H1><DIVCLASS="htmltoc"><P><B>Contents:</B><BR><ACLASS="sect1"HREF="#UPT-ART-4910"TITLE="50.1 UNIX Online Documentation ">UNIX Online Documentation </A><BR><ACLASS="sect1"HREF="ch50_02.htm"TITLE="50.2 The apropos Command ">The apropos Command </A><BR><ACLASS="sect1"HREF="ch50_03.htm"TITLE="50.3 apropos on Systems Without apropos ">apropos on Systems Without apropos </A><BR><ACLASS="sect1"HREF="ch50_04.htm"TITLE="50.4 whatis: One-Line Command Summaries ">whatis: One-Line Command Summaries </A><BR><ACLASS="sect1"HREF="ch50_05.htm"TITLE="50.5 whereis: Finding Where a Command Is Located ">whereis: Finding Where a Command Is Located </A><BR><ACLASS="sect1"HREF="ch50_06.htm"TITLE="50.6 Searching Online Manual Pages ">Searching Online Manual Pages </A><BR><ACLASS="sect1"HREF="ch50_07.htm"TITLE="50.7 How UNIX Systems Remember Their Name ">How UNIX Systems Remember Their Name </A><BR><ACLASS="sect1"HREF="ch50_08.htm"TITLE="50.8 Which Version Am I Using? ">Which Version Am I Using? </A><BR><ACLASS="sect1"HREF="ch50_09.htm"TITLE="50.9 Reading a Permuted Index ">Reading a Permuted Index </A><BR><ACLASS="sect1"HREF="ch50_10.htm"TITLE="50.10 Make Your Own Man Pages Without Learning troff">Make Your Own Man Pages Without Learning troff</A><BR><ACLASS="sect1"HREF="ch50_11.htm"TITLE="50.11 Writing a Simple Man Page with the -man Macros ">Writing a Simple Man Page with the -man Macros </A><BR><ACLASS="sect1"HREF="ch50_12.htm"TITLE="50.12 Common UNIX Error Messages ">Common UNIX Error Messages </A></P><P></P></DIV><DIVCLASS="sect1"><H2CLASS="sect1"><ACLASS="title"NAME="UPT-ART-4910">50.1 UNIX Online Documentation </A></H2><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-58872"></A><ACLASS="indexterm"NAME="AUTOID-58875"></A>The UNIX operating system was one of the first to include onlinedocumentation.It's not the best in the world&nbsp;- most users whohaven't internalized the manual set curse it once a week&nbsp;- but it hasproven surprisingly resilient.What's particularly interesting aboutUNIX's online documentation is that, unlike other early help systems,it isn't an adjunct to another set of printed documentation thatcontains the &quot;real&quot; truth.The online manual is complete,authoritative, and usually more current than any printeddocumentation.</P><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-58878"></A><ACLASS="indexterm"NAME="AUTOID-58880"></A>The basis for UNIX's online documentation is the <EMCLASS="emphasis">man</EM> command.Most simply, you use it as follows:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>man </B></CODE><CODECLASS="replaceable"><I>topic</I></CODE></PRE></BLOCKQUOTE></P><PCLASS="para">where <EMCLASS="emphasis">topic</EM> is usually the name of some command; but it can alsobe the name of a system call, a library routine, an I/O device, or anadministrative file (or file type).The output from <EMCLASS="emphasis">man</EM> is usually sent to a pager like<SPANCLASS="link"><EMCLASS="emphasis">more</EM> (<ACLASS="linkend"HREF="ch25_03.htm"TITLE="Using more to Page Through Files ">25.3</A>)</SPAN>,which allows you to page through.</P><PCLASS="para"><ACLASS="indexterm"NAME="AUTOID-58894"></A>The manual pages are grouped into a number of categories.Unfortunately, there are three slightly different groupings: one forBerkeley-based systems, one for System V, and one for systems derivedfor XENIX.<ACLASS="xref"HREF="ch50_01.htm#UPT-ART-4910-TAB-0"TITLE="UNIX Manual Page Categories">Table 50.1</A>lists these categories.<ACLASS="indexterm"NAME="AUTOID-58898"></A><ACLASS="indexterm"NAME="AUTOID-58901"></A><ACLASS="indexterm"NAME="AUTOID-58903"></A>&#13;</P><TABLECLASS="table"><CAPTIONCLASS="table"><ACLASS="title"NAME="UPT-ART-4910-TAB-0">Table 50.1: UNIX Manual Page Categories</A></CAPTION><THEADCLASS="thead"><TRCLASS="row"VALIGN="TOP"><THCLASS="entry"ALIGN="LEFT"ROWSPAN="1"COLSPAN="1">Category</TH><THCLASS="entry"ALIGN="LEFT"ROWSPAN="1"COLSPAN="1">BSD</TH><THCLASS="entry"ALIGN="LEFT"ROWSPAN="1"COLSPAN="1">System V</TH><THCLASS="entry"ALIGN="LEFT"ROWSPAN="1"COLSPAN="1">Xenix</TH></TR></THEAD><TBODYCLASS="tbody"><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">User commands</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">1</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">1</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">u_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">System calls</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">2</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">2</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">p_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Library routines</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">3</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">3</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">p_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">I/O and special files</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">4</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">7</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">p_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Administrative files</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">5</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">4</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">a_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Games</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">6</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">6 or 1</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">u_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Miscellaneous</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">7</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">5</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">anything goes</TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Administrative commands</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">8</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">8</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">a_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Maintenance commands</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">8</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">1M</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"><EMCLASS="emphasis">u_man </EM>or<EMCLASS="emphasis"> a_man</EM></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Local commands</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">l <EMCLASS="emphasis">(letter)</EM></TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">*</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"></TD></TR><TRCLASS="row"VALIGN="TOP"><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">Obsolete commands</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">o <EMCLASS="emphasis">(letter)</EM></TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1">*</TD><TDCLASS="entry"ROWSPAN="1"COLSPAN="1"></TD></TR></TBODY></TABLE><PCLASS="para">[1]As you can see, System V makes a strange distinction between&quot;administration&quot; and &quot;maintenance&quot;; if you can figure out what theyreally mean, please let us know!To a poor Berkeley soul, this hasnever made sense.Some of these categories are subdivided further; for example, you maysee section 3S (the standard I/O library), 3M (the mathematicslibrary), 1G (Berkeley graphics), 1V (commands derived from System V),and so on.</P><BLOCKQUOTECLASS="footnote"><PCLASS="para">[1] System V and Xenix make no provision for &quot;local&quot; or&quot;obsolete&quot; commands in their <EMCLASS="emphasis">man</EM> system.</P></BLOCKQUOTE><PCLASS="para">If you want to refer to a manual entry in a specific section of themanual, you can give a command like one of these:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>man </B></CODE><CODECLASS="replaceable"><I>section topic</I></CODE>% <CODECLASS="userinput"><B>man -s </B></CODE><CODECLASS="replaceable"><I>section topic</I></CODE></PRE></BLOCKQUOTE></P><PCLASS="para">Some systems require the <EMCLASS="emphasis">-s</EM> &quot;section&quot; option.For example, if you want to read documentation about the<EMCLASS="emphasis">/etc/passwd</EM> file (rather than the <EMCLASS="emphasis">passwd</EM> command) on aSystem V machine, give the command:</P><PCLASS="para"><BLOCKQUOTECLASS="screen"><PRECLASS="screen">% <CODECLASS="userinput"><B>man -s 4 passwd</B></CODE></PRE></BLOCKQUOTE></P><PCLASS="para">This is an easy way to distinguish between topics with the same name,but in different groups.</P><DIVCLASS="sect1info"><PCLASS="SECT1INFO">- <SPANCLASS="authorinitials">ML</SPAN></P></DIV></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="ch49_09.htm"TITLE="49.9 Business Graphics with ipl "><IMGSRC="gifs/txtpreva.gif"SRC="gifs/txtpreva.gif"ALT="Previous: 49.9 Business Graphics with ipl "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="ch50_02.htm"TITLE="50.2 The apropos Command "><IMGSRC="gifs/txtnexta.gif"SRC="gifs/txtnexta.gif"ALT="Next: 50.2 The apropos Command "BORDER="0"></A></TD></TR><TR><TDALIGN="LEFT"VALIGN="TOP"WIDTH="172">49.9 Business Graphics with ipl </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">50.2 The apropos Command </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 &amp; 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