diffpkg: support comparing two given package archives

This adds support similar to diffpkg from the infrastructure repo
that is based on the assumption that two archives can be passed
to the tooling in order to compare them.

1 files changed, 10 insertions, 3 deletions

diff --git a/doc/diffpkg.1.asciidoc b/doc/diffpkg.1.asciidoc
index e95fa43..3fc0f00 100644
--- a/doc/diffpkg.1.asciidoc
+++ b/doc/diffpkg.1.asciidoc
@@ -7,15 +7,22 @@ diffpkg - Compare package files using different modes.
 
 Synopsis
 --------
-diffpkg [OPTIONS] [MODES]
+diffpkg [OPTIONS] [MODES] [FILE|PKGNAME...]
 
 Description
 -----------
 
 Searches for a locally built package corresponding to the PKGBUILD, and
 downloads the last version of that package from the Pacman repositories.
-It then compares them using different modes while using simple tar
-content list by default.
+It then compares the package archives using different modes while using
+simple tar content list by default.
+
+When given one package, use it to diff against the locally built one.
+When given two packages, diff both packages against each other.
+
+In either case, a package name will be converted to a filename from the
+cache, and diffpkg will proceed as though this filename was initially
+specified.
 
 Options
 -------