Hi Stuart,
> > Historically, CSTR 54, page 7, shows that \` is equivalent to \(ga
> > and gives a grave accent, as distinct from ` which just gives plain
> > `.
>
> Where plain ` at one point was an opening quote mark, I assume...
Yes.
> What worries me is cases such as command substitution, e.g. ls -l `find
> -type f -name *foo*` -- the main concern being that if a user copies an
> example, then it should simply work.
Absolutely. Cut-and-paste and copying by typing what's apparently on
the screen must both give working shell quotes for ` ' and ".
> Currently, on UTF-8 locales, groff renders ` as an opening quote mark,
> but the user's shell will complain if they use that. It's easy enough
> to update man pages to use \`, but it seems to me that old man pages
> were correct to use plain `.
I'd have thought so too, but take a look at this 7th Ed. Unix man page
for sh(1) written by Bell Labs themselves.
http://minnie.tuhs.org/UnixTree/V7/usr/man/man1/sh.1.html
Some interesting extracts, first those that show `' is used in normal
writing.
.B PS1
Primary prompt string, by default `$ '.
.B PS2
Secondary prompt string, by default `> '.
unless the
.B export
command is used to bind the shell's
.I parameter
The following prints `a=b c' and `c':
Except for the `special commands' listed below a new
And then uses where the backtick operator is desired.
Explicit null arguments ("" or \'\') are retained.
All characters enclosed between a pair of quote marks (\fB\'\|\'\fP),
except a single quote,
are quoted.
Inside double quotes
(\fB"\|"\fP)
parameter and command substitution occurs and
.B
\\
quotes the characters
.B
\\ \` "
and
.BR $ \|.
The standard output from a command enclosed in
a pair of grave accents
.RB ( \`\|\` )
may be used as part or all
of a word;
trailing newlines are removed.
(So that, for example,
echo ${d\-\`pwd\`}
will only execute
.I pwd
if
.I d
is unset.)
So it seems clear that man pages should use \` or its verbose \(ga
equivalent when they mean a shell backtick operator, ASCII character 96.
Cheers,
Ralph.
