man – macros to typeset manual

nroff −man file ...
troff −man file ...

These macros are used to format pages of this manual.
Except in .LR and .RL requests, any text argument denoted t in the request summary may be zero to six words. Quotes " ... " may be used to include blanks in a ‘word’. If t is empty, the special treatment is applied to the next text input line (the next line that doesn’t begin with dot). In this way, for example, .I may be used to italicize a line of more than 6 words, or .SM followed by .B to make small letters in ‘bold’ font.
A prevailing indent distance is remembered between successive indented paragraphs, and is reset to default value upon reaching a non-indented paragraph. Default units for indents i are ens.
The fonts are
R     roman, the main font, preferred for diagnostics
I     italic, preferred for parameters, short names of commands, names of manual pages, and naked function names
B     ‘bold’, actually the constant width font, preferred for examples, file names, declarations, keywords, names of struct members, and literals (numbers are rarely literals)
L     also the constant width font. In troff L=B; in nroff arguments of the macros .L, .LR, and .RL are printed in quotes; preferred only where quotes really help (e.g. lower-case literals and punctuation).
Type font and size are reset to default values before each paragraph, and after processing font- or size-setting macros.
The −man macros admit equations and tables in the style of eqn(1) and tbl(1), but do not support arguments on .EQ and .TS macros.
These strings are predefined by −man:
\*R   ‘®’, ‘(Reg)’ in nroff.
\*S   Change to default type size. \*9 The root directory of the Plan 9 installation.


troff(1), man(1)

Request Cause If no      Explanation
Break Argument
.B t     no
t=n.t.l.*    Text t is ‘bold’.
.BI t    no
t=n.t.l.    Join words of t alternating bold and italic.
.BR t    no
t=n.t.l.    Join words of t alternating bold and Roman.
.DT     no           Restore default tabs.
.EE     yes          End displayed example
.EX     yes          Begin displayed example
.HP i    yes
i=p.i.*     Set prevailing indent to i. Begin paragraph with hanging indent.
.I t     no
t=n.t.l.    Text t is italic.
.IB t    no
t=n.t.l.    Join words of t alternating italic and bold.
.IP x i yes
x=""     Same as .TP with tag x.
.IR t    no
t=n.t.l.    Join words of t alternating italic and Roman.
.L t     no
t=n.t.l.    Text t is literal.
.LP     yes          Same as .PP.
.LR t    no           Join 2 words of t alternating literal and Roman.
.PD d    no
d=.4v    Interparagraph distance is d.
.PP     yes          Begin paragraph. Set prevailing indent to default.
.RE     yes          End of relative indent. Set prevailing indent to amount of starting .RS.
.RI t    no
t=n.t.l.    Join words of t alternating Roman and italic.
.RL t    no           Join 2 or 3 words of t alternating Roman and literal.
.RS i    yes
i=p.i.     Start relative indent, move left margin in distance i. Set prevailing indent to default for nested indents.
.SH t    yes
t=""      Subhead; reset paragraph distance.
.SM t    no
t=n.t.l.    Text t is small.
.SS t    no
t=""      Secondary subhead.
.TF s    yes          Prevailing indent is wide as string s in font L; paragraph distance is 0.
.TH n c x yes          Begin page named n of chapter c; x is extra commentary, e.g. ‘local’, for page head. Set prevailing indent and tabs to default.
.TP i    yes
i=p.i.     Set prevailing indent to i. Restore default indent if i=0. Begin indented paragraph with hanging tag given by next text line. If tag doesn’t fit, place it on separate line.
.1C     yes          Equalize columns and return to 1-column output
.2C     yes          Start 2-column nofill output
* n.t.l. = next text line; p.i. = prevailing indent

There’s no way to fool troff into handling literal double quote marks " in font-alternation macros, such as .BI.
There is no direct way to suppress column widows in 2-column output; the column lengths may be adjusted by inserting .sp requests before the closing .1C.

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