Question

I have a text file in this format [ONE testing 1 2 3] [TWO lorem ipsum] [ONE 123]

I want to print `[ONE.+]` line by line.

An example output would be

[ONE testing 1 2 3]
[ONE 123]

I’ve tried awk '/\[ONE.+\]/ { print $1 }' but it didn’t work. Can anyone teach me why? And what the correct way is?

Answer 1

awk works line by line, so the expression is only matched once per line. To do it in awk, you can use the match function in a loop. You’d also have to modify your regex to be less greedy, since your expression doesn’t magically stop at the first ].

It might be easier to just use grep:

echo  "[ONE testing 1 2 3] [TWO lorem ipsum] [ONE 123]" | grep -o '\[ONE[^]]*\]'