Gophernicus (the gopher server used at SDF) has a nice script
feature for gophermaps. Any line that starts with '=' is assumed to
refer to a script, and the output is sent to the client.

As an example, in Sander's gopher hole I found a neat
weather-fetching service [0]. Basically, you just 'finger <city
name>@graph.no' ('finger @graph.no' for help), this works for major
cities world-wide. Using gophernicus' script execution feature, I
put this in my gophermap (formatted here but all on one line in my
gophermap).

=/usr/pkg/bin/finger o:montreal@graph.no | grep can | \
/usr/pkg/bin/perl -pe 's{canada/quebec/montreal at (\d+:\d+)} \
{Montreal weather at $1 local time}' | /usr/pkg/bin/par 68

and for my random Firefly quote I use:

=/arpa/ns/s/slugmax/bin/fortune | /usr/bin/fmt

Generally paths will need to be absolute for this to work, so I just
specify them all fully (and this is more secure anyway).

The alternative if your gopher server does not have something like
this is to use a cron to periodically generate some content, and
update a file in your gopherspace (whether gophermap or other). When
SDF used bucktooth I did the Firefly quote that way.

[0] gopher://sdf.org/1/users/sander/term/