Unsorted git

These are things worth remembering, but don’t yet have a home in the organized information on other pages.:

| git branch -avv
| @{upstream} or @{u}
| git add -p
| git status -s
| git commit -v
| git log -Sstring
| Git log with file name
| git blame
| git log -L 1,1:some-file.txt
| https://github.com/github/hub
| git pull -X theirs
| git reset --hard origin/mybranch (and friends - see e.g.: http://stackoverflow.com/questions/9301782/need-to-reset-git-branch-to-origin-version)
| advanced git staging and committing

Fetch a group of remotes:

$ git config remotes.default 'origin bob staging'
$ git remote update
# fetches remotes "origin", "bob", and "staging"

Delete a branch here, and everywhere:

$ git branch -d mybranch  (deletes locally)
$ git push origin :mybranch (uses "git push <remote> <localbranch>:<remotebranch>" syntax to delete remote branch)
$ git fetch --all --prune (use this on other machines to propagate the changes and get rid of "obsolete tracking branches")

Advanced branch diffing

It’s often helpful to get a review of all the commits that are in this branch but that aren’t in your master branch. You can exclude commits in the master branch by adding the –not option before the branch name. This does the same thing as the master..contrib format that we used earlier. For example, if your contributor sends you two patches and you create a branch called contrib and applied those patches there, you can run this:

$ git log contrib --not master
commit 5b6235bd297351589efc4d73316f0a68d484f118
Author: Scott Chacon <schacon@gmail.com>
Date: Fri Oct 24 09:53:59 2008 -0700

seeing if this helps the gem:

commit 7482e0d16d04bea79d0dba8988cc78df655f16a0
Author: Scott Chacon <schacon@gmail.com>
Date: Mon Oct 22 19:38:36 2008 -0700

updated the gemspec to hopefully work better To see what changes each commit introduces, remember that you can pass the -p option to git log and it will append the diff introduced to each commit.

To see a full diff of what would happen if you were to merge this topic branch with another branch, you may have to use a weird trick to get the correct results. You may think to run this:

$ git diff master This command gives you a diff, but it may be misleading. If your master branch has moved forward since you created the topic branch from it, then you’ll get seemingly strange results. This happens because Git directly compares the snapshots of the last commit of the topic branch you’re on and the snapshot of the last commit on the master branch. For example, if you’ve added a line in a file on the master branch, a direct comparison of the snapshots will look like the topic branch is going to remove that line.

If master is a direct ancestor of your topic branch, this isn’t a problem; but if the two histories have diverged, the diff will look like you’re adding all the new stuff in your topic branch and removing everything unique to the master branch.

What you really want to see are the changes added to the topic branch – the work you’ll introduce if you merge this branch with master. You do that by having Git compare the last commit on your topic branch with the first common ancestor it has with the master branch.

Technically, you can do that by explicitly figuring out the common ancestor and then running your diff on it:

$ git merge-base contrib master
$ git diff 36c7db

However, that isn’t convenient, so Git provides another shorthand for doing the same thing: the triple-dot syntax. In the context of the diff command, you can put three periods after another branch to do a diff between the last commit of the branch you’re on and its common ancestor with another branch:

$ git diff master...contrib This command shows you only the work your current topic branch has introduced since its common ancestor with master. That is a very useful syntax to remember.

Next, try to make each commit a logically separate changeset. If you can, try to make your changes digestible

The Git project provides a document that lays out a number of good tips for creating commits from which to submit patches – you can read it in the Git source code in the Documentation/SubmittingPatches file.

First, you don’t want to submit any whitespace errors. Git provides an easy way to check for this – before you commit, run git diff --check, which identifies possible whitespace errors and lists them for you.

Repository status checks

Here’s a small script to check the status of all my repositories so I know what I need to push, pull, etc. As can be seen, it could use some improvements, but it does a good enough job.:


if [[ $1 == "-v" ]] ; then

found_repos=$(find ${HOME} -type d -name ".git")

# FIXME for bare repos
# 1.
#    to get bare repos to see remote branches (git branch -r)
#    add the following to e.g. ${HOME}/.dots/config in the [remote "origin"]
#    section:
#       fetch = +refs/heads/*:refs/remotes/origin/*
# 2. for any bare repos, need to `mkdir .git` for this script to find it

for repo in ${found_repos}
  repo=${repo%/*} # trim ".git" from path
  [ $VERBOSE = 'true' ] && echo "fetching ${repo}"
  cd ${repo}
  result=$(git for-each-ref --format=" %(refname:short) %(push:track)" refs/heads \
           | grep -e 'behind' -e 'ahead' \
           | sed 's/\[\|\]//g' \
           | sed 's/behind /</g' \
           | sed 's/ahead />/g')
  if [ ! -z "${result}" ]
    # shorten the output
    echo --${repo#${HOME}/}--
    echo "${result}"