修改git init默认分支，master改为main

分支默认为main，从git 2.28版本开始支持，确保本地git版本大于等于2.28。

一、查看或升级本地git版本

1、通过brew安装的git，或升级git

$ brew install git

$ brew upgrade git
Warning: git 2.29.2 already installed

2、查看git版本

发现与brew安装的Git没有关联，关联的是Mac默认的Git

$ git --version
git version 2.23.0

3、将git关联到brew安装的Git上

$ brew link git --overwrite
Linking /usr/local/Cellar/git/2.29.2... 209 symlinks created

4、再次查看本地git版本

$ git --version
git version 2.29.2

二、配置

1、查看本地的默认分支配置

$ cat /Users/yuanzhiying/.gitconfig

$ cat /Users/yuanzhiying/.gitconfig
[filter "lfs"]
    clean = git-lfs clean -- %f
    smudge = git-lfs smudge -- %f
    process = git-lfs filter-process
    required = true
[user]
    name = yuanzhiying
    email = *********@qq.com

2、设置main为git init默认分支

$ git config --global init.defaultBranch main

3、再次查看本地配置

$ cat /Users/yuanzhiying/.gitconfig
[filter "lfs"]
    clean = git-lfs clean -- %f
    smudge = git-lfs smudge -- %f
    process = git-lfs filter-process
    required = true
[user]
    name = yuanzhiying
    email = ********@qq.com
[init]
    defaultBranch = main

4、验证

# yuanzhiying @ yingiMac in ~/test [12:18:54]
$ git init
已初始化空的 Git 仓库于 /Users/yuanzhiying/test/.git/

# yuanzhiying @ yingiMac in ~/test on git:main x [12:18:57]