only in a single sgml file, i have.

     <ulink url="https://github.com/postgres/postgres/commit/2af07e2f7"> [2af07e2f7] </ulink>
     <ulink url="https://github.com/postgres/postgres/commit/165d581f1"> [165d581f1] </ulink>,
     <ulink url="https://github.com/postgres/postgres/commit/617f9b7d4"> [617f9b7d4] </ulink>

is possible to confugure base url, so i don’t need write
“https://github.com/postgres/postgres/commit”
all the time?
so it will become something like:

<ulink url="$variable/2af07e2f7"> [2af07e2f7] </ulink>