+The bit before `wget` is here to prevent updating the wiki while it is
+updating, which can lead to a deadlock. Indeed, when the wiki is edited via
+web, or a tag page is automatically added, IkiWiki pushes the changes to the
+Git machine. Then, the hook on this latter machine tries to pull changes from
+the IkiWiki machine, and here is the deadlock. Explanations of the command:
+
+* `git log -1 --format=format:%ae HEAD`: Looks for the user name of the
+ latest commit.
+* `grep -e '@web$' -e 'USER@HOST': Check whether this last commit was pushed
+ from the IkiWiki machine (change `USER@HOST` to the appropriate string).
+* `wget ...`: If the last commit does not come from the IkiWiki machine
+ (which means it comes from another machine), update the wiki.