suggestions for generating diffs through the revision list

> I am try to walk the revision history for a given path and analyze the
> diff (as compared to its parent).  What is the proper way of doing that?
>
> I noticed a bunch of 'library' calls such as
>
> init_revsion(&revs);
> setup_revisions(argc, argv, &revs, "HEAD");
> prepare_revision_walk(&revs, NULL);
> commit = get_revision(&revs);
>
> But what I can't find is the way to generate diffs.  I see lots and lots
> of code to do it, but every builtin seems to do it differently.  Not
> knowing the internals that well, I was hoping for some advice.
>
> I stumbled upon calls like
>
> run_diff_files
> run_diff_index
>
> but I haven't seen how to use them correctly.

> Don Zickus <dzickus@redhat.com> writes:
> 
> > I am try to walk the revision history for a given path and analyze the
> > diff (as compared to its parent).  What is the proper way of doing that?
> >
> > I noticed a bunch of 'library' calls such as
> >
> > init_revsion(&revs);
> > setup_revisions(argc, argv, &revs, "HEAD");
> > prepare_revision_walk(&revs, NULL);
> > commit = get_revision(&revs);
> >
> > But what I can't find is the way to generate diffs.  I see lots and lots
> > of code to do it, but every builtin seems to do it differently.  Not
> > knowing the internals that well, I was hoping for some advice.
> >
> > I stumbled upon calls like
> >
> > run_diff_files
> > run_diff_index
> >
> > but I haven't seen how to use them correctly.
> 
> Documentation/technical/api-*.txt