Escaping dots in groff

Question

According to info groff (section 5.11 Character Translations), \. should print just the dot. However, this is not what seems to happen. If I render this manpage

.TH x x x x
\.SH foo

I get foo rendered as a section heading, and .SH is not printed.

So, why does this happen, and how do I escape the dot (and the apostrophe) at the begginning of the line in groff?

Answer 1

To escape dot at the beginning of line write use \[char46] :

\[char46]SH foo

prints

.SH foo

This is an expected behavior but should be fixed in manual page. Here is a bug report.

Below you can read the description of both \\ (shortened) and \. (from info pages).

-- Escape: \\
[...]

`\\' is a `delayed' backslash; more precisely, it is the default
escape character followed by a backslash, which no longer has
special meaning due to the leading escape character. It is _not_
an escape sequence in the usual sense! In any unknown escape
sequence `\X' the escape character is ignored and X is printed.
But if X is equal to the current escape character, no warning is
emitted.

As a consequence, only at top-level or in a diversion a backslash
glyph is printed; in copy-in mode, it expands to a single
backslash which then combines with the following character to an
escape sequence.

[...]

-- Escape: \.
Similar to `\\', the sequence `\.' isn't a real escape sequence.
As before, a warning message is suppressed if the escape character
is followed by a dot, and the dot itself is printed.

Answer 2

Simply prepend the dot with a zero-width character:

\&. -- this a a dot.

or switch temporarily to another control character:

.cc #
. -- this is a dot.
#cc