git

clean repo

    //  cd to folder
    //  run commands in terminal
    git fetch --depth=1
    git reflog expire --expire-unreachable=now --all
    git gc --aggressive --prune=all

basics

    //  remove .ds_store files
    find . -name .DS_Store -print0 | xargs -0 git rm -f --ignore-unmatch
    
    git stash
    git stash list
    git stash apply
    git stash drop
    
    git reset --hard
    
    git difftool
    
    //  revert a modified (single) file back to previous commit
    git checkout -- file
    //  example
    git checkout -- sidebar.php
    
    git checkout  
    git checkout 088ecd favicon.ico
    
    //  delete git
    rm -rf .git
    
    //  set new origin [use the second one for https url]
    git remote set-url origin git://new.url.here
    git remote set-url origin https://github.com/USERNAME/OTHERREPOSITORY.git
    
    //  change git origin url
    https://help.github.com/articles/changing-a-remote-s-url/
    
    //  recover deleted file
    git log --diff-filter=D --summary | grep delete
    git log -- [deleted-filename]
    git checkout $commit~1 filename

gitignore

    #  custom
    _src/
    _core/
    _adtl/
    #  end custom
    
    .DS_Store
    .AppleDouble
    .LSOverride
    
    #  icon must end with two \r
    Icon
    
    #  thumbnails
    ._*
    
    #  files that might appear in the root of a volume
    .DocumentRevisions-V100
    .fseventsd
    .Spotlight-V100
    .TemporaryItems
    .Trashes
    .VolumeIcon.icns
    
    #  directories potentially created on remote AFP share
    .AppleDB
    .AppleDesktop
    Network Trash Folder
    Temporary Items
    .apdisk
    
    #  wordpress
    *.log
    .htaccess
    sitemap.xml
    sitemap.xml.gz
    wp-config.php
    wp-content/advanced-cache.php
    wp-content/backup-db/
    wp-content/backups/
    wp-content/blogs.dir/
    wp-content/cache/
    wp-content/upgrade/
    wp-content/uploads/
    wp-content/wp-cache-config.php