如何简化此命令以仅使用 awk？

Question

awk '/user/ {print $1 }' /etc/userdomains | sed 's/://'

/etc/userdomains 的格式是

domain.tld: user
otherdomain.tld: otheruser

Answer 1

最简单的方法是将字段分隔符设置为“:”

awk -F":" '$2~/user/{print $1}' /etc/userdomains

And if you want to check for exact username, 

awk -F"[ \t]*:[ \t]*" '$2=="user"{print $1}' /etc/userdomains