[git] Find which commit is currently checked out in Git

I'm in the middle of a git bisect session.

What's the command to find out which commit (SHA1 hash) I am currently on? git status does not provide this.

Edit: I guess calling git log and looking at first entry works?

If you want to extract just a simple piece of information, you can get that using git show with the --format=<string> option...and ask it not to give you the diff with --no-patch. This means you can get a printf-style output of whatever you want, which might often be a single field.

For instance, to get just the shortened hash (%h) you could say:

$ git show --format="%h" --no-patch
4b703eb

If you're looking to save that into an environment variable in bash (a likely thing for people to want to do) you can use the $() syntax:

$ GIT_COMMIT="$(git show --format="%h" --no-patch)"

$ echo $GIT_COMMIT
4b703eb

The full list of what you can do is in git show --help. But here's an abbreviated list of properties that might be useful:

• %H commit hash
• %h abbreviated commit hash
• %T tree hash
• %t abbreviated tree hash
• %P parent hashes
• %p abbreviated parent hashes
• %an author name
• %ae author email
• %at author date, UNIX timestamp
• %aI author date, strict ISO 8601 format
• %cn committer name
• %ce committer email
• %ct committer date, UNIX timestamp
• %cI committer date, strict ISO 8601 format
• %s subject
• %f sanitized subject line, suitable for a filename
• %gD reflog selector, e.g., refs/stash@{1}
• %gd shortened reflog selector, e.g., stash@{1}

You can just do:

git rev-parse HEAD

To explain a bit further: git rev-parse is git's basic command for interpreting any of the exotic ways that you can specify the name of a commit and HEAD is a reference to your current commit or branch. (In a git bisect session, it points directly to a commit ("detached HEAD") rather than a branch.)

Alternatively (and easier to remember) would be to just do:

git show

... which defaults to showing the commit that HEAD points to. For a more concise version, you can do:

$ git show --oneline -s
c0235b7 Autorotate uploaded images based on EXIF orientation

Use git show, which also shows you the commit message, and defaults to the current commit when given no arguments.

$ git rev-parse HEAD
273cf91b4057366a560b9ddcee8fe58d4c21e6cb

Update:

Alternatively (if you have tags):

(Good for naming a version, not very good for passing back to git.)

$ git describe
v0.1.49-localhost-ag-1-g273cf91

Or (as Mark suggested, listing here for completeness):

$ git show --oneline -s
c0235b7 Autorotate uploaded images based on EXIF orientation