man.7

操作系统设计与实现源码

.\" man(7) manpage by [e-mail] (Bill Rosenkranz)
.\" Modified a bit for Minix by Kees J. Bot ([e-mail])
.\"
.TH MAN 7
.SH NAME
man - nroff macro package for manual pages
.SH SYNOPSIS
.B nroff \-man
.IR file " ..."
.SH DESCRIPTION
.de SP
.if t .sp 0.4
.if n .sp
..
These macros are used to lay out reference pages for manuals.
.PP
Any text argument
.I t
may be zero to six words.  Quotes may be used to include blanks in a 'word'.
.I Text
can be empty, but unlike normal \s-2UNIX\s+2 macros, the next line is not used.
.PP
A prevailing indent distance is remembered between successive
indented paragraphs, and is reset to default value upon
reaching a non-indented paragraph (i.e. at .SH or .SS).
.SH FILES
.TP 25n
/usr/lib/tmac/tmac.an
For standard Minix nroff.
.TP
/usr/lib/cawf/man.mac
For cawf.
.SH SEE ALSO
.BR nroff (1),
.BR man (1).
.SH "REQUEST SUMMARY"
.nf
.ta +15n +9n
Request	Cause	Explanation
	Break? 

\&.B t	no	Text t is bold. Quote to imbed blanks.
\&.I t	no	Text t is italic. Quote to imbed blanks.
\&.IP x	yes	Set prevailing indent to 5. Begin
		indented paragraph with hanging tag
		given by first argument.	Tag x is
		always placed on a separate line.
\&.LP	yes	Same as .PP.
\&.PP	yes	Begin paragraph.	Set prevailing
		indent to 5.
\&.RE	yes	End of relative indent.	Set prevailing
		indent to amount of starting .RS.
\&.RS	yes	Start relative indent, move left margin
		in distance 5.
\&.SH t	yes	Subhead. Quote to imbed blanks.
\&.SS t	yes	Subsection. Quote to imbed blanks. No
		indent for t.
\&.TH n s c v d	yes	Begin page named n of chapter s; c is
		the chapter name; d is the date of the
		most recent change; v is version number.
		Sets prevailing indent and tabs to 5.
.fi
.SH EXAMPLE
The following illustrates some of the requests available
with this macro package:
.RS
.nf
\&.\e" this is a comment
\&.TH DEMO 1
\&.SH NAME
demo \e- show how to use \e-man package
\&.SH SYNOPSIS
\&.B demo
\&.RI [ options ]
\&.IR file " ..."
\&.SH DESCRIPTION
This is a test for showing how to use the
\&.BR nroff (1)
man package. It shows how to use .TH, .SH, .PP, .B, .I, and .IP
commands.
\&.PP
This will be a new paragraph. You can also use normal
\&.BR nroff (1)
commands in the text.
\&.SS Nroff Commands
\&.IP '\ee"'
This is the comment command.  \e" You won't see this.
\&.IP nf
No fill mode (the normal mode is fill mode where things
get justified right and left).
\&.IP fi
Re-enter fill mode.
\&.IP br
Break line here no matter what.
\&.IP sp
Vertical space (also causes a break to occur).
\&.sp
Note that to continue an indent and make a new paragraph (as
is the case here), just put in a space (.sp).
\&.PP
Now we should be at a new paragraph.
.fi
.RE
.PP
Executing
.B nroff \-man demo.man
results in the following output:  (Ignoring page headers and footers)
.PP
.RS
.B NAME
.RS
demo \e- show how to use \e-man package
.RE
.SP
.B SYNOPSIS
.RS
.B demo
.RI [ options ]
.IR file " ..."
.RE
.SP
.B DESCRIPTION
.RS
This is a test for showing how to use the
.BR nroff (1)
man package. It shows how to use .TH, .SH, .PP, .B, .I, and .IP
commands.
.SP
This will be a new paragraph. You can also use normal
.BR nroff (1)
commands in the text.
.RE
.SP
.ti +2n
.B Nroff Commands
.RS
.RS
.ta +5n
.SP
.ti -5n
\&'\e"'	This is the comment command.
.SP
.ti -5n
nf	No fill mode (the normal mode is fill mode where things
get justified right and left).
.SP
.ti -5n
fi	Re-enter fill mode.
.SP
.ti -5n
br	Break line here no matter what.
.SP
.ti -5n
sp	Vertical space (also causes a break to occur).
.sp
Note that to continue an indent and make a new paragraph (as
is the case here), just put in a space (.sp).
.RE
.SP
Now we should be at a new paragraph.
.RE
.RE
.SH CONVENTIONS
A typical manual page for a command or function is laid out as follows:
.nf

     .TH TITLE [1-8]
          The name of the command or function in upper-case,
          which serves as the title of the manual page. This is
          followed by the number of the section in which it
          appears.

     .SH NAME
          name - one-line summary

          The name, or list of names, by which the command is
          called, followed by a dash and then a one-line summary
          of the action performed.  All in roman font, this sec-
          tion contains no troff(1) commands or escapes, and no
          macro requests.  It is used to generate the whatis(1)
          database.

     .SH SYNOPSIS

          Commands:

               The syntax of the command and its arguments as
               typed on the command line.  When in boldface, a
               word must be typed exactly as printed.  When in
               italics, a word can be replaced with text that you
               supply.  Syntactic symbols appear in roman face:

               [ ]  An argument, when surrounded by brackets is
                    optional.

               |    Arguments separated by a vertical bar are
                    exclusive.  You can supply only item from
                    such a list.

               ...  Arguments followed by an elipsis can be
                    repeated.  When an elipsis follows a brack-
                    eted set, the expression within the brackets
                    can be repeated.

          Functions:

               If required, the data declaration, or #include
               directive, is shown first, followed by the  func-
               tion declaration. Otherwise, the function declara-
               tion is shown.

     .SH DESCRIPTION
          A narrative description of the command or function in
          detail, including how it interacts with files or data,
          and how it handles the standard input, standard output
          and standard error.

          Filenames, and references to commands or functions
          described elswhere in the manual, are italicised.  The
          names of options, variables and other literal terms are
          in boldface.

     .SH OPTIONS
          The list of options along with a description of how
          each affects the commands operation.

     .SH ENVIRONMENT
          Environment variables used.

     .SH FILES
          A list of files associated with the command or func-
          tion.

     .SH "SEE ALSO"
          A comma-separated list of related manual pages,
          followed by references to other published materials.
          This section contains no troff(1) escapes or commands,
          and no macro requests.

     .SH DIAGNOSTICS
          A list of diagnostic messages and an explanation of
          each.

     .SH NOTES
          Any additional notes such as installation-dependent
          functionality.

     .SH BUGS
          A description of limitations, known defects, and possi-
          ble problems associated with the command or function.

     .SH AUTHOR
          The program's author and any pertinent release info.

     .SH VERSION
          The program's current version number and release date.
.fi
.SH BUGS
Even though
.BR cawf (1)
has a better chance at formatting a random manual page then the standard
Minix nroff, it has two annoying bugs in its macro set.  Both .PP and .IP 
reset the indentation level to the level set by .SH.  This means that
you can't use them in a piece of text indented by .RS.  For .IP this is
troublesome, you can see why in the unformatted source of this text.  .PP
can simply be replaced by .sp, or better yet, by .SP with the following
macro defined somewhere in your text:
.PP
.RS
.nf
\&.de SP
\&.if t .sp 0.4
\&.if n .sp
\&..
.fi
.RE
.PP
This will make .SP use 4/10 of a line if formatted by troff, just like .PP.