===== Overview =====

Discussion of ''git log'', with emphasis on reachability.

===== Reachability =====

''git log'' displays repository history based on //reachability//:

<code>
        o---o---o---o---o  master
             \       \
              o---o---o---o---o  next
                           \
                            o---o---o  topic
</code>

Identify the specific starting point(s):

<code>
$ git log master
$ git log topic master
</code>

Identify revisions not of interest:

<code>
$ git log next --not master
$ git log next ^master
$ git log next topic ^master
$ git log b1 b2 b3 ... ^b8 ^b9 v1.0 v2.0 ...
</code>

Given this history:

<code>
        o---o---o---o---o  master
             \       \
              o---o---o---o---o  next
                           \
                            o---o---o  topic
</code>

there is a special notation for the most common exclusion (//remember this one for rebasing//):

<code>
$ git log next ^master
$ git log master..next
$ git log next..topic
</code>

===== Why is "git log" so slow? =====

If you want to see the log of all changes to a single file:

<code>
$ git log --oneline -- scripts/dtc/Makefile
</code>

it will take a while as Git does //not// store per-file changes with the file.

===== diff-filter =====

Show only commits that deleted files:

<code>
$ git log --diff-filter=D --summary
</code>