roff.9

操作系统设计与实现源码

.CD "roff \(en text formatter"
.SX "roff\fR [\fB\(enhs\fR]\fR [\fB+\fIn\fR] [\fB\(en\fIn\fR] \fIfile\fR ..."
.FL "\(enh" "Expand tabs to spaces in output"
.FL "\(ens" "Stop before each page; continue on DEL"
.FL "+\fIn\fP" "Start printing with page \fIn\fP"
.FL "\(en\fIn\fP" "Stop after page \fIn\fP"
.EX "roff file" "Run off \fIfile\fP"
.EX "roff +5 file" "Run off \fIfile\fP starting at page 5"
.PP
.I Roff
is a text formatter.
Its input consists of the text to be output, intermixed with formatting commands.
A formatting command is a line containing the control character followed by
a two character command name, and possibly one or more arguments.
The control character is initially \*(OQ.\*(CQ (dot).
The formatted output is produced on standard output.
.PP
The formatting commands are listed below, with
.I n
being a number,
.I c
being a character, and
.I t
being a title.
A + before \fIn\fP means it may be signed, indicating a positive or negative
change from the current value.
Initial values for
.I n ,
where relevant, are given in parentheses.
.HS
.ta 0.25i 1i
.nf
	\fB.ad\fP	Adjust right margin.
	\fB.ar\fP	Arabic page numbers.
	\fB.br\fP	Line break.  Subsequent text will begin on a new line.
	\fB.bl\fP n	Insert \fIn\fP blank lines.
	\fB.bp\fP +n	Begin new page and number it \fIn\fP. No \fIn\fP means +1.
	\fB.cc\fP c	Control character is set to \fIc\fP.
	\fB.ce\fP n	Center the next \fIn\fP input lines.
	\fB.de\fP zz	Define a macro called \fIzz\fP. A line with \*(OQ..\*(CQ ends definition.
	\fB.ds\fP	Double space the output. Same as \fB.ls 2\fP.
	\fB.ef\fP t	Even page footer title is set to \fIt\fP.
	\fB.eh\fP t	Even page header title is set to \fIt\fP.
	\fB.fi\fP	Begin filling output lines as full as possible.
	\fB.fo\fP t	Footer titles (even and odd) are set to \fIt\fP.
	\fB.hc\fP c	The character \fIc\fP (e.g., %) tells \fIroff\fP where hyphens are permitted.
	\fB.he\fP t	Header titles (even and odd) are set to \fIt\fP.
	\fB.hx\fP	Header titles are suppressed.
	\fB.hy\fP n	Hyphenation is done if \fIn\fP is 1, suppressed if it is 0. Default is 1.
	\fB.ig\fP	Ignore input lines until a line beginning with \*(OQ..\*(CQ is found.
	\fB.in\fP n	Indent \fIn\fP spaces from the left margin; force line break.
	\fB.ix\fP n	Same as \fI.in\fP but continue filling output on current line.
	\fB.li\fP n	Literal text on next \fIn\fP lines.  Copy to output unmodified.
	\fB.ll\fP +n	Line length (including indent) is set to \fIn\fP (65).
	\fB.ls\fP +n	Line spacing: \fIn\fP (1) is 1 for single spacing, 2 for double, etc.
	\fB.m1\fP n	Insert \fIn\fP (2) blank lines between top of page and header.
	\fB.m2\fP n	Insert \fIn\fP (2) blank lines between header and start of text.
	\fB.m3\fP n	Insert \fIn\fP (1) blank lines between end of text and footer.
	\fB.m4\fP n	Insert \fIn\fP (3) blank lines between footer and end of page.
	\fB.na\fP	No adjustment of the right margin.
	\fB.ne\fP n	Need \fIn\fP lines.  If fewer are left, go to next page.
	\fB.nn\fP +n	The next \fIn\fP output lines are not numbered.
	\fB.n1\fP	Number output lines in left margin starting at 1.
	\fB.n2\fP n	Number output lines starting at \fIn\fP.  If 0, stop numbering.
	\fB.ni\fP +n	Indent line numbers by \fIn\fP (0) spaces.
	\fB.nf\fP	No more filling of lines.
	\fB.nx\fP f	Switch input to file \fIf\fP.
	\fB.of\fP t	Odd page footer title is set to \fIt\fP.
	\fB.oh\fP t	Odd page header title is set to \fIt\fP.
	\fB.pa\fP +n	Page adjust by \fIn\fP (1).  Same as .bp
	\fB.pl\fP +n	Paper length is \fIn\fP (66) lines.
	\fB.po\fP +n	Page offset.  Each line is started with \fIn\fP (0) spaces.
	\fB.ro\fP	Page numbers are printed in Roman numerals.
	\fB.sk\fP n	Skip \fIn\fP pages (i.e., make them blank), starting with next one.
	\fB.sp\fP n	Insert \fIn\fP blank lines, except at top of page.
	\fB.ss\fP	Single spacing.  Equivalent to .ls 1.
	\fB.ta\fP	Set tab stops, e.g., .ta 9 17 25 33 41 49 57 65 73 (default).
	\fB.tc\fP c	Tabs are expanded into \fIc\fP.  Default is space.
	\fB.ti\fP n	Indent next line \fIn\fP spaces; then go back to previous indent.
	\fB.tr\fP ab	Translate \fIa\fP into \fIb\fP on output.
	\fB.ul\fP n	Underline the letters and numbers in the next \fIn\fP lines.
.fi