linux - 编写多个 sed 命令的更简洁的方法？

Question

是否有更 DRY 的方式来编写以下命令(将它们放在 bash shell 脚本中):

sudo sed -i 's/^#PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config
sudo sed -i 's/PermitRootLogin yes/PermitRootLogin no/' /etc/ssh/sshd_config

sudo sed -i 's/^#PermitEmptyPasswords yes/PermitEmptyPasswords no/' /etc/ssh/sshd_config
sudo sed -i 's/PermitEmptyPasswords yes/PermitEmptyPasswords no/' /etc/ssh/sshd_config

sudo sed -i 's/^#PasswordAuthentication yes/PasswordAuthentication no/' /etc/ssh/sshd_config
sudo sed -i 's/PasswordAuthentication yes/PasswordAuthentication no/' /etc/ssh/sshd_config

sudo sed -i 's/^#X11Forwarding yes/X11Forwarding no/' /etc/ssh/sshd_config
sudo sed -i 's/X11Forwarding yes/X11Forwarding no/' /etc/ssh/sshd_config

Answer 1

由于要匹配的模式相似，您可以对 4 个字符串进行交替并捕获它。使字符串开头的 # 可选。

以下将把它们合二为一:

sed -i -r 's/^#?(PermitRootLogin|PermitEmptyPasswords|PasswordAuthentication|X11Forwarding) yes/\1 no/' /etc/ssh/sshd_config

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如果您的 sed 版本不支持扩展的正则表达式，您可以说:

sed -i 's/^#\{0,1\}\(PermitRootLogin\|PermitEmptyPasswords\|PasswordAuthentication\|X11Forwarding\) yes/\1 no/' /etc/ssh/sshd_config