Thanks for the info about groff. You're right, tzdb man pages are
supposed to be portable to both groff and traditional troff. For the
latter I test with /usr/bin/nroff and /usr/bin/troff on Solaris 10,
which is the oldest troff I know that is still supported.
On 2022-11-23 13:40, G. Branden Robinson wrote:
Strictly, this string definition should be updated to use the font's
minus sign even if the formatter is groff (the `.g` register
interpolates a true value).
.ie \n(.g \{\
. ds : \:
. ds - \f(CW\-\fP
.\}
If we did that, Groff would set a source string like "\*-\*-help" as
"−−help", with two instances of U+2212 MINUS SIGN instead of U+002D
HYPHEN-MINUS. Therefore people couldn't cut and paste code examples out
of HTML or PDF, and into the shell.
"\f(CW-\fP" is used instead of plain "-" because when the output is PDF,
it is more clearly visible to humans as a hyphen-minus instead of as a
hyphen (U+2010 HYPHEN).
Most people won't see a difference because groff 1.22.4 (and earlier
releases going back to, I think, 2009) the man(7) macro package remaps
the hyphen to the minus sign on the 'utf8' output device.
I noticed the abovementioned problem with PDF output, and I still see it
with groff 1.22.4.
I see a different issue with groff 1.22.4 on Ubuntu 22.10: I cannot
easily see the difference between "\f(CR-\fP" and "\f(CR\-\fP" on output
to PDF. If I cut from the output PDF and paste into Emacs or the
terminal, the former is indeed U+002D and the latter U+2202 and the
difference is readily visible in Emacs or the terminal; but it's not
readily visible in the PDF. However, this glitch is not a serious issue
for man pages since examples always contain hyphen-minuses not minus
signs, so I didn't worry about it. I assume that it's yet another font
thing, since the problem doesn't occur in the default Roman font.
I also note that "CW" is an old, AT&T device-independent
troff-compatible font name.[3] groff's preferred name for this face is
"CR", because for the past couple of decades a monospace font (often
Courier) has generally been available in all four styles (roman,
oblique, bold, and bold-oblique).
Thanks, I didn't know that was preferred. I installed the attached patch
into the tzdb development repository
From 220c21f6b4167378f463828e6921c281a85abe1f Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@xxxxxxxxxxx>
Date: Fri, 25 Nov 2022 15:56:52 -0800
Subject: [PROPOSED] Use CR font instead of CW
Suggested by G Branden Robinson in:
https://mm.icann.org/pipermail/tz/2022-November/032336.html
---
newctime.3 | 2 +-
newstrftime.3 | 4 ++--
newtzset.3 | 2 +-
time2posix.3 | 2 +-
tzfile.5 | 2 +-
tzselect.8 | 2 +-
zdump.8 | 6 +++---
zic.8 | 2 +-
8 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/newctime.3 b/newctime.3
index 2907f856..e25d841e 100644
--- a/newctime.3
+++ b/newctime.3
@@ -5,7 +5,7 @@
asctime, ctime, difftime, gmtime, localtime, mktime \- convert date and time
.SH SYNOPSIS
.nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
.el .ds - \-
.B #include <time.h>
.PP
diff --git a/newstrftime.3 b/newstrftime.3
index d68bc337..d5d8ee10 100644
--- a/newstrftime.3
+++ b/newstrftime.3
@@ -40,7 +40,7 @@
strftime \- format date and time
.SH SYNOPSIS
.nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
.el .ds - \-
.B #include <time.h>
.PP
@@ -55,7 +55,7 @@ strftime \- format date and time
.ie '\(rq'' .ds rq \&"\"
.el .ds rq \(rq\"
.de c
-.ie \n(.g \f(CW\\$1\fP\\$2
+.ie \n(.g \f(CR\\$1\fP\\$2
.el \\$1\\$2
..
.de q
diff --git a/newtzset.3 b/newtzset.3
index c3742850..1e75acf0 100644
--- a/newtzset.3
+++ b/newtzset.3
@@ -5,7 +5,7 @@
tzset \- initialize time conversion information
.SH SYNOPSIS
.nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
.el .ds - \-
.B #include <time.h>
.PP
diff --git a/time2posix.3 b/time2posix.3
index e7c69206..e13c431c 100644
--- a/time2posix.3
+++ b/time2posix.3
@@ -5,7 +5,7 @@
time2posix, posix2time \- convert seconds since the Epoch
.SH SYNOPSIS
.nf
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
.el .ds - \-
.B #include <time.h>
.PP
diff --git a/tzfile.5 b/tzfile.5
index 9d312255..c3e86c62 100644
--- a/tzfile.5
+++ b/tzfile.5
@@ -11,7 +11,7 @@ tzfile \- timezone information
.de q
\\$3\*(lq\\$1\*(rq\\$2
..
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
.el .ds - \-
The timezone information files used by
.BR tzset (3)
diff --git a/tzselect.8 b/tzselect.8
index 53a34cf6..846b867b 100644
--- a/tzselect.8
+++ b/tzselect.8
@@ -4,7 +4,7 @@
.SH NAME
tzselect \- select a timezone
.SH SYNOPSIS
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
.el .ds - \-
.ds d " degrees
.ds m " minutes
diff --git a/zdump.8 b/zdump.8
index 1ff92639..170e18d6 100644
--- a/zdump.8
+++ b/zdump.8
@@ -18,7 +18,7 @@ zdump \- timezone dumper
.de q
\\$3\*(lq\\$1\*(rq\\$2
..
-.ie \n(.g .ds - \f(CW-\fP
+.ie \n(.g .ds - \f(CR-\fP
.el .ds - \-
The
.B zdump
@@ -151,7 +151,7 @@ Here is an example of the output, with the leading empty line omitted.
tabbed columns line up.)
.nf
.sp
-.if \n(.g .ft CW
+.if \n(.g .ft CR
.if t .in +.5i
.if n .in +2
.nr w \w'1896-01-13 'u+\n(.i
@@ -184,7 +184,7 @@ UT, a standard time abbreviated HST.
Here are excerpts from another example:
.nf
.sp
-.if \n(.g .ft CW
+.if \n(.g .ft CR
.if t .in +.5i
.if n .in +2
TZ="Europe/Astrakhan"
diff --git a/zic.8 b/zic.8
index 8b77ea12..f345f944 100644
--- a/zic.8
+++ b/zic.8
@@ -24,7 +24,7 @@ zic \- timezone compiler
.el .ds > \(ra
.ie \n(.g \{\
. ds : \:
-. ds - \f(CW-\fP
+. ds - \f(CR-\fP
.\}
.el \{\
. ds :
--
2.37.2
