Re: [Groff] Trying to escape user input.

[Clarke Echols]

If what you are picking up as user input contains text with a line
starting with ".", insert "\&" in front of it.  That places a
zero-width space at the start of the line and puts the dot in
third place on the line so it gets ignored as a command.  Thus
a line starting with ".rt" becomes "\&.rt".

Clarke

Mike Burns wrote:
> I'm working on a document that will have certain sections replaced with user
> input, and I'd like to make sure that the user input doesn't execute any
> roff code.
>
> I'm having trouble figuring out how to escape a "." after a newline.
>
>
> Looking at the man pages I thought I could just change all "." after a
> newline to "\.", and that would escape it, but this doesn't seem to work.  I
> created a tiny 2-line roff input program to show my problem.
>
> ----------------foo.t--------------
> There are many things I'd like to know about the way that roff works.
> \.this is a line that starts with a <.>
> -------------------------------------
>
>
> I execute groff with
>
> groff -ms -Tascii foo.t
>
> and this gets written to stderr
>
> foo.t:2: warning: macro `this' not defined
>
> without the -ms package, the warning is not written to stderr, but the 2nd
> line still doesn't show up in the output stream.
>
> I'm running groff version 1.19.2
>
> Thanks for any advice you can give.
>
>   mike