方法一:修改 /etc/paths
/usr/local/bin /usr/bin /bin /usr/sbin /sbin
方法二:修改 ~/.bash_profile
alias ls="ls -G" export PATH=/usr/local/apache-maven-3.3.9/bin:$PATH
/usr/local/bin /usr/bin /bin /usr/sbin /sbin
alias ls="ls -G" export PATH=/usr/local/apache-maven-3.3.9/bin:$PATH