使用sed替换除注释以外的第一次发生(Replacing first occurence except comments using sed)

使用sed替换除注释以外的第一次发生(Replacing first occurence except comments using sed)

我有一个形式的文本文件：

a = 1 #b = [2,3] c = 4 d = [5,6] e = [7,8]

我想用一个数字替换括号（和括号）内的模式，但忽略注释中的匹配，最好使用sed。

对于只有一个匹配行的文件，我已经使用过

sed -i "/^#/!s/\[.*\]/9/" myfile

如果还有更多，如何修改它以仅替换第一场比赛？

I have a text file of the form:

a = 1 #b = [2,3] c = 4 d = [5,6] e = [7,8]

I want to replace the pattern inside the brackets (and the brackets) with a number, but ignore matches in the comments, preferably using sed.

For files with exactly one matching line, I've used

sed -i "/^#/!s/\[.*\]/9/" myfile

How can this be modified to replace only the first match if there are more?

最满意答案

这是正确的，因为只是改变了第一次发生。

awk '!end && /^[^#]+ = \[/ {$3="9"; end=1}1' myfile

如果没有结束标志，并且行不是从#开始并匹配到= [ ，则更改第三列并设置标志以防止在下次出现时更改。

a = 1

#b = [2,3]

c = 4

d = 9

e = [7,8] <---这不会随意改变

This is the correct, because changing just the first occurence.

awk '!end && /^[^#]+ = \[/ {$3="9"; end=1}1' myfile

if there is not end flag and line is not beggining from # and match to = [, then change the third column and set the flag to prevent changing in next occurences.

a = 1

#b = [2,3]

c = 4

d = 9

e = [7,8] <--- this is not changed as you want