grep去除空行与注释行

不显示空行:

grep -v ^$ /etc/ssh/sshd_config

不显示注释行:

grep -v ^# /etc/ssh/sshd_config

不显示空行及注释行:

grep -v "^$\|^#" /etc/ssh/sshd_config

允许Debian使用root用户和密码ssh登录:

echo "PermitRootLogin yes" >> /etc/ssh/sshd_config
echo "PasswordAuthentication yes" >> /etc/ssh/sshd_config
systemctl restart sshd.service