Number of Commits between two Commitishes

Solution 1:

Before I give you an answer, consider this commit graph:

        o -----------
       /             \
... - A - o - o - o - B
       \         /
        o ----- o

Each o represents a commit, as do A and B (they're just letters to let us talk about specific commits). How many commits are there between commits A and B?

That said, in more linear cases, just use git rev-list --count A..B and then decide what you mean by "between" (does it include B and exclude A? that's how git rev-list --count will behave). In branchy cases like this, you'll get all the commits down all the branches; add --first-parent, for instance, to follow just the "main line".

(You also mentioned "commitish", suggesting that we might have annotated tags. That won't affect the output from git rev-list, which only counts specific commits.)

Edit: Since git rev-list --count A..B includes commit B (while omitting commit A), and you want to exclude both end-points, you need to subtract one. In modern shells you can do this with shell arithmetic:

count=$(($(git rev-list --count A..B) - 1))

For instance:

$ x=$(($(git rev-list --count HEAD~3..HEAD) - 1))
$ echo $x
2

(this particular repo has a very linear graph structure, so there are no branches here and there are two commits "between" the tip and three-behind-the-tip). Note, however, that this will produce -1 if A and B identify the same commit:

$ x=$(($(git rev-list --count HEAD..HEAD) - 1))
$ echo $x
-1

so you might want to check that first:

count=$(git rev-list --count $start..$end)
if [ $count -eq 0 ]; then
    ... possible error: start and end are the same commit ...
else
    count=$((count - 1))
fi

Solution 2:

$ git log 375a1..58b20 --pretty=oneline | wc -l

Specify your start commit followed by your end commit, and then count the lines. That should be the count of commits between those two commit ranges. Use the --pretty=oneline formatting so that each commit takes up a single line.

Note that using two dots (375a1..58b20) is different than using three dots (375a1...58b20); see What are the differences between double-dot “..” and triple-dot “…” in Git commit ranges? for more information about this and to figure out which one you want to use.

As for the GUI in GitHub, I don't know of a way to accomplish this same task. But that should be trivial, as the above is the possible way to do it directly using Git and Bash.

Solution 3:

Another ONE LINER

git rev-list newer ^older --pretty=oneline --count

Use revision numbers or SHAs:

git rev-list db8fb95e6256bd52a668bae82d8b5a73152869fa ^1aeae117c58c173fee9cb3550297498142887aa5 --pretty=oneline --count

[newer] and [older] can be SHA’s, branches or tags.
Important: If you have a complicated git graph you should read @torek 's excellent answer.
Credit goes to @matt wilkie in his comment and the original source.