gbranden pushed a commit to branch master
in repository groff.
commit 431d48b8451334e73730b17a7044a25f7003943f
Author: G. Branden Robinson <g.branden.robin...@gmail.com>
AuthorDate: Thu Jul 10 09:32:12 2025 -0500
doc/*,man/*: Fix style nits.
Clarify discussions, tighten wording, and parallelize documents.
---
doc/groff.texi.in | 256 +++++++++++++++++++++++++++++++++++----------------
man/groff.7.man | 8 +-
man/groff_diff.7.man | 110 ++++++++++++----------
3 files changed, 242 insertions(+), 132 deletions(-)
diff --git a/doc/groff.texi.in b/doc/groff.texi.in
index f7388ba29..19f076b61 100644
--- a/doc/groff.texi.in
+++ b/doc/groff.texi.in
@@ -1330,7 +1330,8 @@ and
requests,
which are disabled by default because they allow an untrusted input
document to run arbitrary commands
-and write to arbitrary file names.@footnote{GNU @command{troff}
+and write to arbitrary file names.@footnote{GNU
+@command{troff} @c GNU
does not,
however,
accept newlines
@@ -4749,11 +4750,9 @@ of its own.
The internals of
@code{groff}
@file{ms}
-differ from those of
-@acronym{AT&T}
+differ from those of @acronym{AT&T}
@file{ms}.
-Documents that depend upon implementation details of
-@acronym{AT&T}
+Documents that depend upon implementation details of @acronym{AT&T}
@file{ms}
may not format properly with
@code{groff}
@@ -5437,7 +5436,7 @@ that the word has been broken,
and that its remainder lies on the next.
Hyphenation break points can be manually specified;
GNU
-@command{troff}
+@command{troff} @c GNU
also uses a hyphenation algorithm
and language-specific pattern files
(based on
@@ -6916,7 +6915,7 @@ tab,
newline,
space,
or invalid as GNU
-@command{troff}
+@command{troff} @c GNU
input;
recall @ref{Input Format}.
Thus, the identifiers @samp{br}, @samp{PP}, @samp{end-list},
@@ -7788,7 +7787,7 @@ undefined macro (namely @samp{''}).
Start a whole-line comment; read everything up to and including the next
newline in copy mode (@pxref{Copy Mode}) and discard it.
GNU
-@command{troff}
+@command{troff} @c GNU
introduced this extension to avoid the problems described above.
(@code{\"}
is still widely seen,
@@ -7913,7 +7912,7 @@ interpolated. @xref{Auto-increment}.)
@cindex untokenized escape sequence, @code{\R}
@code{\R}
is not tokenized when GNU
-@command{troff}
+@command{troff} @c GNU
reads its input;
it updates only the formatter's register dictionary
and does not contribute (directly) to output.
@@ -8036,7 +8035,7 @@ If
@var{existing-register}
is undefined,
GNU
-@command{troff}
+@command{troff} @c GNU
produces a warning in category
@samp{reg}
and ignores the request.
@@ -13713,7 +13712,7 @@ If
@var{existing-name}
is undefined,
GNU
-@command{troff}
+@command{troff} @c GNU
produces a warning in category
@samp{mac}
and ignores the request.
@@ -13944,7 +13943,7 @@ comparisons in other programming languages.
@noindent
Since
GNU
-@command{troff}
+@command{troff} @c GNU
reads comparands protected with
@code{\?}
in copy mode (@pxref{Copy Mode}),
@@ -17424,7 +17423,7 @@ performs the copy only when the diversion is emitted.
it is therefore an error to use this request in safer mode,
which is the default.
Invoke GNU
-@command{troff}
+@command{troff} @c GNU
or a front end with the
@option{-U}
option to enable unsafe mode.
@@ -17863,7 +17862,7 @@ these produce warnings in category @samp{char}.
@endDefesc
GNU
-@command{troff}
+@command{troff} @c GNU
also permits the interpolation of macro or string contents
as a device extension command.
@@ -18351,7 +18350,7 @@ Set the input line number
optionally,
the file name)
GNU
-@command{troff}
+@command{troff} @c GNU
uses when reporting diagnostics.
The argument becomes the input line number of the
@emph{next}
@@ -19009,7 +19008,7 @@ implementations.
@cindex @code{pi} request, disabled by default
@cindex @code{sy} request, disabled by default
GNU
-@command{troff}
+@command{troff} @c GNU
operates in ``safer'' mode by default;
to mitigate risks from untrusted input documents,
the
@@ -19046,23 +19045,54 @@ GNU
therefore makes available a
@dfn{compatibility mode}
in an effort to keep documents prepared for AT&T
-@command{troff}
+@command{troff} @c AT&T
rendering well.
@cindex long names
@cindex names, long
@cindex @code{\*}, incompatibilities with @acronym{AT&T} @code{troff}
@cindex @code{\n}, incompatibilities with @acronym{AT&T} @code{troff}
-Identifier names of arbitrary length may be GNU @code{troff}'s most
-obvious innovation. @acronym{AT&T} @code{troff} interprets
-@samp{.dsabcd} as defining a string @samp{ab} with contents @samp{cd}.
-Normally, GNU @code{troff} interprets this as a call of a macro named
-@code{dsabcd}. @acronym{AT&T} @code{troff} also interprets @samp{\*[}
-and @samp{\n[} as an interpolation of a string or register,
-respectively, named @samp{[}. In GNU @code{troff}, however, the
-@samp{[} is normally interpreted as delimiting a long name. In
-compatibility mode, GNU @code{troff} interprets names in the traditional
-way; they thus can be two characters long at most.
+Identifier names of arbitrary length may be
+GNU
+@command{troff}'s @c GNU
+most obvious innovation.
+@acronym{AT&T}
+@command{troff} @c AT&T
+interprets
+@samp{.dsabcd}
+as defining a string
+@samp{ab}
+with contents
+@samp{cd}.
+Normally,
+GNU
+@command{troff} @c GNU
+interprets this input as calling a macro named
+@code{dsabcd}.
+@acronym{AT&T}
+@code{troff} @c AT&T
+also interprets
+@samp{\*[}
+and
+@samp{\n[}
+as interpolating a string or register,
+respectively,
+named
+@samp{[}.
+GNU
+@command{troff}, @c GNU
+however,
+normally interprets
+@samp{[}
+as bracketing a long name
+(with
+@samp{]}
+at the distal end).
+In compatibility mode,
+GNU
+@command{troff} @c GNU
+interprets names in the traditional way;
+they thus can be two characters long at most.
@DefreqList {cp, [@Var{b}]}
@DefregListEndx {.C}
@@ -19078,16 +19108,38 @@ Compatibility mode is also enabled by the @option{-C}
command-line
option.
@endDefreq
-@DefreqList {do, name}
+@DefreqList {do, name [@Var{argument} @r{@dots{}}]}
@DefregListEndx {.cp}
-The @code{do} request interprets the string, request, diversion, or
-macro @var{name} (along with any further arguments) with compatibility
-mode disabled. Compatibility mode is restored (only if it was active)
-when the @emph{expansion} of @var{name} is interpreted; that is, the
-restored compatibility state applies to the contents of the macro,
-string, or diversion @var{name} as well as data read from files or pipes
-if @var{name} is any of the @code{so}, @code{soquiet}, @code{mso},
-@code{msoquiet}, or @code{pso} requests.
+Interpret the string,
+request,
+diversion,
+or macro
+@var{name}
+(along with any further arguments)
+with compatibility mode disabled.
+Compatibility mode is restored
+(only if it was active)
+when the interpolation
+of
+@var{name}
+is interpreted;
+that is,
+the restored compatibility state applies to the request or
+contents of the macro,
+string,
+or diversion
+@var{name},
+its arguments,
+and data read from files or pipes if
+@var{name}
+is the
+@code{so},
+@code{soquiet},
+@code{mso},
+@code{msoquiet},
+or
+@code{pso}
+request.
The following example illustrates several aspects of @code{do} behavior.
@@ -19130,14 +19182,27 @@ compatibility mode off with @samp{.cp 0}, then
restore it from that
register at the end with @samp{.cp \n(_C}. At the same time, a modular
design of a document or macro package may lead you to multiple layers of
inclusion. You cannot use the same register name everywhere lest you
-``clobber'' the value from a preceding or enclosing context. The
-two-character register name space of @acronym{AT&T} @code{troff} is
-confining and mnemonically challenging; you may wish to use the more
-capacious name space of GNU @code{troff}. However, attempting @samp{.nr
-_my_saved_C \n(.C} will not work in compatibility mode; the register
-name is too long. ``This is exactly what @code{do} is for,'' you think,
-@samp{.do nr _my_saved_C \n(.C}. The foregoing will always save zero to
-your register, because @code{do} turns compatibility mode @emph{off}
+``clobber'' the value from a preceding or enclosing context.
+The two-character register name space of @acronym{AT&T}
+@command{troff} @c AT&T
+is confining,
+but employing
+GNU
+@command{troff}'s @c GNU
+more capacious one,
+as with
+@samp{.nr _my_saved_C \n(.C},
+will not work in compatibility mode;
+the register name is too long.
+Employing the
+@code{do}
+request is no help:@:
+@samp{.do nr _my_saved_C \n(.C}
+always saves zero to the register,
+because
+@code{do}
+turns compatibility mode
+@emph{off}
while it interprets its argument list.
@need 375 @c 250 < x < 500
@@ -19148,27 +19213,30 @@ To robustly save compatibility mode before switching
it off, use
.cp 0
@endExample
-at the beginning of your file, followed by
+at the beginning of your file,
+followed by
@Example
.cp \n[_my_saved_C]
.do rr _my_saved_C
@endExample
-at the end. As in the C language, we all have to share one big
-name space, so choose a register name that is unlikely to collide with
-other uses.
+at the end.
+As the C language exposes application programs' symbols
+to those defined by libraries,
+@code{roff} documents share a name space with macro packages;
+choose a register name that is unlikely to collide with other uses.
@endDefreq
@cindex additional delimiters accepted by @acronym{AT&T} @code{troff}
@cindex delimiters, additional, accepted by @acronym{AT&T} @code{troff}
In compatibility mode,
GNU
-@command{troff}
-accepts several characters as delimiters that it ordinarily rejects,
-because they are meaningful in numeric expressions and therefore
-potentially ambiguous to the document maintainer.
-The set of additional delimiters comprises
+@command{troff} @c GNU
+accepts several characters as delimiters that it ordinarily rejects
+because they can begin numeric expressions and therefore
+may be ambiguous to the document maintainer.
+This set of additional delimiters comprises
@samp{0123456789+-(.|}.
@cindex input level in delimited arguments
@@ -19176,7 +19244,7 @@ The set of additional delimiters comprises
@cindex delimited arguments, incompatibilities with @acronym{AT&T} @code{troff}
Normally,
GNU
-@command{troff}
+@command{troff} @c GNU
keeps track of delimited arguments' interpolation depth.
In compatibility mode,
it does not.
@@ -19216,9 +19284,8 @@ no longer recognizes a control character on the input
line;
AT&T
@command{troff} @c AT&T
does.
-
-For example, this code produces bold output in both cases, but the text
-differs.
+Thus the next example produces bold output in both modes,
+but the text differs.
@Example
.de xx
@@ -19229,6 +19296,7 @@ Hello!
@result{} Hello! @r{(compatibility mode)}
@endExample
+@need 1000
@cindex @code{\s}, incompatibilities with @acronym{AT&T} @code{troff}
Normally, the syntax form @code{\s}@var{n} accepts only a single
character (a digit) for @var{n}, consistently with other forms that
@@ -19391,7 +19459,7 @@ with spaces in their names,
but requires more care with trailing comments,
and doubling of an initial neutral double quote
@samp{"}
-if the file name contains one.
+if the file name has one.
@cindex output device name string (@code{.T}), in other implementations
GNU @code{troff} predefines a string @code{.T} containing the argument
@@ -19410,11 +19478,23 @@ registers; GNU @code{troff} honors such requests.
@xref{Built-in
Registers}.
@cindex output device usage register (@code{.T}), incompatibility with
@acronym{AT&T} @code{troff}
-The (read-only) register @code{.T} interpolates@tie{}1 if GNU
-@code{troff} is called with the @option{-T} command-line option, and
-0@tie{}otherwise. This behavior differs from AT&T @code{troff}, which
-interpolated@tie{}1 only if @code{nroff} was the formatter and was
-called with @option{-T}.
+The (read-only) register
+@code{.T}
+interpolates@tie{}1
+if
+GNU
+@command{troff} @c GNU
+is run with the
+@option{-T}
+option,
+and 0@tie{}otherwise.
+In contrast,
+AT&T
+@command{troff} @c AT&T
+interpolated@tie{}1 only if
+@command{nroff}
+was the formatter and was run with
+@option{-T}.
@cindex @code{lf} request, incompatibilities with @acronym{AT&T} @code{troff}
@acronym{AT&T} @code{troff} and other implementations handle the
@@ -19446,9 +19526,15 @@ arguments are given, and it exits with a failure
status instead of a
successful one.
@cindex @code{bp} request, incompatibilities with @acronym{AT&T} @code{troff}
-The @code{bp} request differs from @acronym{AT&T} @code{troff}: GNU
-@code{troff} does not accept a scaling unit on the argument, a page
-number; the former (somewhat uselessly) does.
+The
+@code{bp}
+request differs from @acronym{AT&T}
+@command{troff}:@: @c AT&T
+GNU
+@command{troff} @c GNU
+does not accept a scaling unit on the argument,
+a page number;
+the former does (uselessly).
@cindex @code{pm} request, incompatibilities with @acronym{AT&T} @code{troff}
In @acronym{AT&T}
@@ -19470,10 +19556,15 @@ and otherwise dumps
the @acronym{JSON}-encoded name and contents of each named argument.
@cindex @code{ss} request, incompatibilities with @acronym{AT&T} @code{troff}
-Unlike @acronym{AT&T} @code{troff}, GNU @code{troff} does not ignore the
-@code{ss} request if the output is a terminal device; instead, the
-values of minimum inter-word and additional inter-sentence space are
-each rounded down to the nearest multiple of@tie{}12.
+AT&T
+@command{troff} @c AT&T
+ignores the
+@code{ss}
+request if the output is a terminal device;
+GNU
+@command{troff} @c GNU
+rounds down the values of minimum inter-word and additional
+inter-sentence space each to the nearest multiple of@tie{}12.
@cindex @code{bd} request, incompatibilities with @acronym{AT&T} @code{troff}
@cindex @code{cs} request, incompatibilities with @acronym{AT&T} @code{troff}
@@ -19499,7 +19590,7 @@ Glyphs represent graphemes
(supplied by the output device)
and populate diversions
or the pending output line.
-The formatting process converts characters into
+Formatting converts characters into
(sequences of)
glyphs.
GNU
@@ -19526,16 +19617,16 @@ applying the
@code{asciify}
or
@code{unformat}
-requests to diversion converts some of its nodes back into characters.
+requests to a diversion converts some of its nodes back into characters.
Where the formatter cannot recover the character representation
of a node,
it stores a null character in the character list
corresponding to a single node in the node list.
Consequently,
-a glyph node does not behave like a character
-when it is processed by a macro:@:
-it does not inherit any of the special properties
+a glyph node does not behave as a character does
+in macro interpolation:@:
+it does not inherit special properties
that the character from which it was constructed might have had.
For example,
the input
@@ -19576,10 +19667,17 @@ backslash's common use as a @code{troff} escape
character---perhaps in
discussion of character sets or other programming languages---is
the character escape @code{\(rs} or @code{\[rs]}, for ``reverse
solidus'', from its name in the @acronym{ECMA}-6 and @w{ISO 10646}
-standards.@footnote{The @code{rs} special character identifier was not
-defined in @acronym{AT&T} @code{troff}'s font description files, but is
-in those of its descendant Heirloom Doctools @code{troff}, as of the
-latter's 060716 release (July 2006).}
+standards.@footnote{@acronym{AT&T}
+@command{troff}'s
+font description files
+did not define the
+@code{rs}
+special character,
+but those of
+its descendant Heirloom Doctools
+@command{troff} @c Heirloom
+do,
+as of its 060716 release (July 2006).}
@c The foregoing once said "lineal" descendant; that appears not to be
@c true. Heirloom Doctools troff is based on Open Solaris troff, which
@c descends from DWB 2.0 troff (effectively a fork). "Lineal"
diff --git a/man/groff.7.man b/man/groff.7.man
index 4215c2e7b..e2a3c66b0 100644
--- a/man/groff.7.man
+++ b/man/groff.7.man
@@ -3240,20 +3240,18 @@ Direct output to diversion
.IR ident .
.
.TPx
-.REQ .do "name \fR\&.\|.\|.\&\fP"
+.REQ .do "name argument \fR\&.\|.\|.\&\fP"
Interpret the string,
request,
diversion,
or macro
.I name
-(along with any arguments)
+(along with any further arguments)
with compatibility mode disabled.
.
Compatibility mode is restored
(only if it was active)
-when the
-.I expansion
-of
+when the interpolation of
.I name
is interpreted.
.
diff --git a/man/groff_diff.7.man b/man/groff_diff.7.man
index ce5e4e230..f5438d032 100644
--- a/man/groff_diff.7.man
+++ b/man/groff_diff.7.man
@@ -2552,13 +2552,13 @@ output as the argument to a device extension command.
.
.TP
.BI .do\~ name\~\c
-.RI [ arg \~.\|.\|.]
+.RI [ argument \~.\|.\|.]
Interpret the string,
request,
diversion,
or macro
.I name
-(along with any arguments)
+(along with any further arguments)
with compatibility mode disabled.
.
Compatibility mode is restored
@@ -2567,20 +2567,22 @@ when the interpolation of
.I name
is interpreted;
that is,
-the restored compatibility state applies to the contents of the macro,
+the restored compatibility state applies to the request or
+contents of the macro,
string,
or diversion
+.IR name ,
+its arguments,
+and data read from files or pipes if
.I name
-as well as data read from files or pipes if
-.I name
-is any of the
+is the
.RB \[lq] so \[rq],
.BR soquiet ,
.BR mso ,
.BR msoquiet ,
or
.B pso
-requests.
+request.
.
.
.TP
@@ -5286,15 +5288,23 @@ namely the output device
or
.BR utf8 ).
.
-The (read-only)
-.I register
+The (read-only) register
.B .T
-interpolates\~1 if GNU
+interpolates\~1
+if
+GNU
.I troff \" GNU
is run with the
.B \-T
-command-line option,
+option,
and 0\~otherwise.
+In contrast,
+AT&T
+.I troff \" AT&T
+interpolated\~1 only if
+.I nroff
+was the formatter and was run with
+.BR \-T .
.
.
.br
@@ -6031,7 +6041,8 @@ rendering well.
.
.
.P
-Identifier names of arbitrary length may be GNU
+Identifier names of arbitrary length may be
+GNU
.IR troff 's \" GNU
most obvious innovation.
.
@@ -6047,7 +6058,7 @@ with contents
Normally,
GNU
.I troff \" GNU
-interprets this as a call of a macro named
+interprets this input as calling a macro named
.RB \[lq] dsabcd \[rq].
.
AT&T
@@ -6056,23 +6067,26 @@ also interprets
.B \[rs]*[
and
.B \[rs]n[
-as an interpolation of a string or register,
+as interpolating a string or register,
respectively,
-called
+named
.RB \[lq] [ \[rq].
.
-In GNU
+GNU
.IR troff , \" GNU
however,
-the
+normally interprets
.RB \[lq] [ \[rq]
-is normally interpreted as beginning the enclosure of a long identifier.
+as bracketing a long name
+(with
+.RB \[lq] ] \[rq]
+at the distal end).
.
In compatibility mode,
GNU
.I troff \" GNU
interprets names in the traditional way,
-which means that they are limited to one or two characters.
+they thus can be two characters long at most.
.
See the
.B \-C
@@ -6131,24 +6145,21 @@ You cannot use the same register name everywhere lest
you
.
The two-character register name space of AT&T
.I troff \" AT&T
-is confining and mnemonically challenging;
-you may wish to use
+is confining,
+but employing
GNU
.IR troff 's \" GNU
-more capacious name space.
-.
-However,
-attempting
+more capacious one,
+as with
.RB \[lq] ".nr _my_saved_C \[rs]n(.C" \[rq]
will not work in compatibility mode;
the register name is too long.
.
-\[lq]This is exactly what
-.B .do
-is for,\[rq] you think,
+Employing the
+.RB \[lq] do \[rq]
+request is no help:
.RB \[lq] ".do nr _my_saved_C \[rs]n(.C" \[rq].
-.
-The foregoing will always save zero to your register,
+always saves zero to the register,
because
.RB \[lq] do \[rq]
turns compatibility mode
@@ -6161,8 +6172,8 @@ In compatibility mode,
GNU
troff \" GNU
accepts several characters as delimiters that it ordinarily rejects,
-because they are meaningful in numeric expressions and therefore
-potentially ambiguous to the document maintainer.
+because they can begin numeric expressions and therefore
+may be ambiguous to the document maintainer.
.
The set of additional delimiters comprises
.RB \[lq] 0123456789+\-(.| \[rq].
@@ -6299,7 +6310,7 @@ with spaces in their names,
but requires more care with trailing comments,
and doubling of an initial neutral double quote
.RB \[lq] \[dq] \[rq]
-if the file name contains one.
+if the file name has one.
.
.
.P
@@ -6546,9 +6557,7 @@ GNU
.I troff \" GNU
does not accept a scaling unit on the argument,
a page number;
-the former
-(somewhat uselessly)
-does.
+the former does (uselessly).
.
.
.P
@@ -6606,7 +6615,7 @@ Glyphs represent graphemes
and populate diversions
or the pending output line.
.
-The formatting process converts characters into
+Formatting converts characters into
(sequences of)
glyphs.
.
@@ -6636,7 +6645,7 @@ applying the
.B \%asciify
or
.B \%unformat
-requests to diversion converts some of its nodes back into characters.
+requests to a diversion converts some of its nodes back into characters.
.
Where the formatter cannot recover the character representation
of a node,
@@ -6644,9 +6653,9 @@ it stores a null character in the character list
corresponding to a single node in the node list.
.
Consequently,
-a glyph node does not behave like a character
-when it is processed by a macro:
-it does not inherit any of the special properties
+a glyph node does not behave as a character does
+in macro interpolation:
+it does not inherit special properties
that the character from which it was constructed might have had.
.
.
@@ -6679,13 +6688,18 @@ programming languages\[em]is the character escape
or
.BR \[rs][rs] ,
for \[lq]reverse solidus\[rq],
-from its name in the ECMA-6 (ISO/IEC\~646) standard.
-.
-[This escape sequence is not portable to AT&T
-.IR troff , \" AT&T
-but is to its descendant
-Heirloom Doctools
-.IR troff ,
+from its name in the ECMA-6 and ISO\~10646 standards.
+.
+[AT&T
+.I troff 's \" AT&T
+font description files
+did not define the
+.B rs
+special character,
+but those of
+its descendant Heirloom Doctools
+.I troff \" Heirloom
+do,
as of its 060716 release (July 2006).]
.\" The foregoing once said "lineal" descendant; that appears not to be
.\" true. Heirloom Doctools troff is based on Open Solaris troff, which
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