Commit messages in Git’s history

Script for batch modifying Git history commit author information, rewriting Git history records using git filter-branch.

You provided the script to modify the author information in the Git repository history in bulk. The overall approach is correct, but using an array (e.g., OLD_EMAILS=("...")) within the git filter-branch’s --env-filter might cause compatibility issues because some shell environments (such as /bin/sh) do not support array syntax. To improve compatibility, it’s recommended to replace the array with space-separated strings and use a for loop to iterate through each old email address. Here is an example of the modified script:

#!/bin/sh

git filter-branch --env-filter '
OLD_EMAILS="TianlongXiang51@gmail.com nick@qq.com tianlongxiang51@gmail.com"
CORRECT_NAME="tianlong.xiang"
CORRECT_EMAIL="tianlong.xiang@foxmail.com"

for OLD_EMAIL in $OLD_EMAILS
do
    if [ "$GIT_COMMITTER_EMAIL" = "$OLD_EMAIL" ]
    then
        export GIT_AUTHOR_NAME="$CORRECT_NAME"
        export GIT_AUTHOR_EMAIL="$CORRECT_EMAIL"
    fi
    if [ "$GIT_AUTHOR_EMAIL" = "$OLD_EMAIL" ]
    then
        export GIT_COMMITTER_NAME="$CORRECT_NAME"
        export GIT_COMMITTER_EMAIL="$CORRECT_EMAIL"
    fi
done
' --tag-name-filter cat -- --branches --tags

Notes:

It is recommended to back up your repository before executing this script to prevent any unexpected issues.
This operation rewrites Git history, modifying the author information of commits, which may cause changes in commit hash values.
If you have already pushed the changes to a remote repository, you need to use a forced push: Please use forced pushes cautiously, especially in collaborative projects, to avoid affecting others.

Count all unique authors’ email addresses in the repository

git log --format='%an <%ae>' | sort -u