Git command to display HEAD commit id?

What command can I use to print out the commit id of HEAD?

This is what I'm doing by hand:

$ cat .git/HEAD
ref: refs/heads/v3.3
$ cat .git/refs/heads/v3.3
6050732e725c68b83c35c873ff8808dff1c406e1

But I need a script that can reliably pipe the output of some command to a text file such that the text file contains exactly the commit id of HEAD (nothing more or less, and not just a ref). Can anyone help?

Solution 1:

Use the command:

git rev-parse HEAD

For the short version:

git rev-parse --short HEAD

Solution 2:

git log -1

for only commit id

git log | head -n 1 

Solution 3:

Old thread, still for future reference...:) even following works

git show-ref --head

by default HEAD is filtered out. Be careful about following though ; plural "heads" with a 's' at the end. The following command shows branches under "refs/heads"

 git show-ref --heads

Solution 4:

You can specify git log options to show only the last commit, -1, and a format that includes only the commit ID, like this:

git log -1 --format=%H

If you prefer the shortened commit ID:

git log -1 --format=%h