如何用sed删除特定文件行？

[arthurchen]

需要删除一个文件中行长度超过20个字符的行，请问如何用sed实现

[eexpress]

行长度超过20个字符
/.{20,}/d

[tenzu]

神是正则小王子

[arthurchen]

行长度超过20个字符
/.{20,}/d

Thanks, but it doesn't work, I used sed -i -e '/.{20,}/d' file to remove the line contains more than 20 characters, is it right?
Can you please express the expression?

[lilydjwg]

行长度超过20个字符
/.{20,}/d

Thanks, but it doesn't work, I used sed -i -e '/.{20,}/d' file to remove the line contains more than 20 characters, is it right?
Can you please express the expression?

这个是超过20个字节的吧？那个 {} 貌似需要转义。

[arthurchen]

不用sed了, 换成awk 'length < 20' 输出小于20个字符的行, 貌似这样速度还快些
因为我的是文件全是英文字符，所以字节和字符个数是一样的

[lexdene]

关注。

[scutdk]

要用sed的话，需要 sed -i -r -e 因为使用了ERE，所以加-r选项