Find to which git commit a file belongs?

Question

Given a random file, is there a canonical method to determine from the command line whether the file belongs to a particular commit?

This is similar to stack overflow question find-out-which-git-commit-a-file-was-taken-from except that I wish to be able to use it in scripts and also not create a temporary branch.

Answer 1

Below is an excerpt of a script that I have been using for the purpose. I hacked it together using my limited git knowledge and pieces of other scripts that I have found on the web. It works well enough, but I often find that there are easier ways to do things in git than what I have learned by trial and error.

FILE=$1

# git hash for file
HASH=`git hash-object $FILE`

# git revisions for file
REVS=`git log --pretty=%H -- $FILE`

# check each revision for checksum match
for rev in $REVS; do
    POSSIBLE=`git ls-tree $rev $FILE | awk '{print $3}'`
    if [[ $HASH == $POSSIBLE ]]; then
        echo $rev
    fi
done