修改文件匹配WORD1和NOT WORD2（Sed / Awk）中的行

Question

I need to add kernel parameters to lines not already containing them. (Don't want to add it to all lines in case it's already there.)

I've built this awk command to do it in buffer, but having trouble getting it into the file itself since awk lacks the ability to edit in place like sed . (However I can't figure out how to do this type of match with sed .)

awk '/\\tkernel/&&!/audit=1/ { print $0" audit=1"; }' /etc/grub.conf

This looks for lines matching "kernel" and NOT "audit=1" (appending " audit=1" as necessary.)

Tagged as sed/awk, but open to other suggestions.

Answer 1

使用sed：

sed -i '/kernel/{/audit=1/!s/$/ audit=1/}' /etc/grub.conf

Answer 2

The in-place editing functionality of sed uses a temporary file that without a suffix, is used to replace the existing file. For example, this:

sed -i '/\tkernel/ { /audit=1/!s/$/ audit=1/ }' /etc/grub.conf

is the same as this:

sed '/\tkernel/ { /audit=1/!s/$/ audit=1/ }' /etc/grub.conf > tmp && mv tmp /etc/grub.conf

The -i flag just sugar coats the process. Therefore, you can simply apply the same logic to your awk command:

awk '/\tkernel/ && !/audit=1/ { print $0, "audit=1"; next }1' /etc/grub.conf > tmp && mv tmp /etc/grub.conf