How can I reset or revert a file to a specific revision?

Question

I have made some changes to a file which has been committed a few times as part of a group of files, but now want to reset/revert the changes on it back to a previous versio

Answer 1

git-aliases, awk and shell-functions to the rescue!

git prevision  

where is the number of revisions of the file to rollback for file .
For example, to checkout the immediate previous revision of a single file x/y/z.c, run

git prevision -1 x/y/z.c

---

How git prevision works?

Add the following to your gitconfig

[alias]
        prevision = "!f() { git checkout `git log --oneline $2 |  awk -v commit="$1" 'FNR == -commit+1 {print $1}'` $2;} ;f"

The command basically

• performs a git log on the specified file and
• picks the appropriate commit-id in the history of the file and
• executes a git checkout to the commit-id for the specified file.

Essentially, all that one would manually do in this situation,
wrapped-up in one beautiful, efficient git-alias - git-prevision