Git Tips

Git's HEAD pointer

For me, the key to understanding how git works came when I grasped that the HEAD notation is similar to a window that can slide over a set of commits. The window can be moved to show a different commit, which makes it become the current commit.

HEAD is actually a reference, or a pointer, to a particular commit. There's a separate HEAD for your local repository, and the remote repository (normally called 'origin'). When you complete a merge both the local and remote HEAD's will point to the same commit.

Set git difftool and mergetool to use vimdiff

git difftool --tool=vimdiff --no-prompt

git config --global diff.tool vimdiff

git config --global merge.tool vimdiff

Git delete remote branch

git push origin --delete feature/worthless-hack-branch

Git undo last commit (that's a tilde, not a dash)

soft leaves change in staging

git reset --soft HEAD~1

hard deletes change

git reset --hard HEAD~1

Git change date of commit

git commit --amend --no-edit --date="2018-04-09"

OR

export GIT_COMMITTER_DATE="Tues 20 Oct 1987 12:00:00 PST" 
git commit --amend --no-edit --date $GIT_COMMITTER_DATE

Git change committer name and email

#!/bin/sh
git filter-branch --env-filter 
'OLD_EMAIL="bad-email-address@example.com"
CORRECT_NAME="FULL NAME"
CORRECT_EMAIL="EMAIL ADDRESS@example.com"
if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
then
  export GIT_COMMITTER_NAME="$CORRECT_NAME"
  export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
fi
if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
  then
  export GIT_AUTHOR_NAME="$CORRECT_NAME"
  export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
fi' --tag-name-filter cat -- --branches --tags