Examples

1. Check the length of the checked-out commit:

   git commit-message-summary-length

2. Amend if the message is longer than you prefer:

   git commit-message-summary-length || git commit --amend

3. Print ok if origin/main's second ancestor commit's message is 47 characters long or shorter:

   git commit-message-summary-length --error-after=47 --log-level=0 origin/main~2 && echo ok

4. Configure for GitHub, which in some parts of the web UI truncates messages longer than 72 characters to 69 characters:

   git config --global commit-message-summary-length.warnafter 69
   git commit-message-summary-length

5. Automatically run after every commit:

   1. Configure git config --global init.templatedir if you haven't already.

      git config --global init.templatedir
      
      # if no output
      git config --global init.templatedir ~/.config/.git-templates`

   2. Add a post-commit hook file, and add a git-commit-message-summary-length command to it.

      mkdir -p $(git config --global init.templatedir)/hooks
      echo "git commit-message-summary-length" >> $(git config --global init.templatedir)/hooks/post-commit
      chmod +x $(git config --global init.templatedir)/hooks/post-commit

6. Type less:

   git config --global alias.l commit-message-summary-length

   Or if your shell has native abbreviations (like fish) or an abbreviations plugin (like zsh's zsh-abbr, by the creator of git-commit-message-summary-length), create an abbreviation for git commit-message-summary-length. (l is nice and short.)