Re: misbehavior of groff -o

[Dave Kemper]

On 3/17/20, Doug McIlroy <doug@cs.dartmouth.edu> wrote:
> This command
>         groff -o /dev/null
> correctly gives the diagnostic
>         troff: bad output page list
> then loops forever, regardless of the input file.

Doug,

I can't reproduce this, either on groff 1.22.4 (which I presume you
were using in 2020 when you reported the problem) or in 1.23.

When I give only "groff -o /dev/null" at the shell prompt, it does
indeed (correctly) give the diagnostic you said, but then waits for
stdin from the terminal -- as it would do if you said only "groff"
with no -o option.  You can type groff input and hit Control-D when
you're done, as with any program reading from stdin.

If I say "groff -o /dev/null file.tr", groff does give the diagnostic
but then processes the input file and exits normally.

Is it possible you mistook the wait for stdin input for an infinite
loop?  (Unlikely, if you got the same results when specifying an input
file.)  If not, can you give more details on how to reproduce this?