Question

This is an extension of my previous question. In that question, I needed to retrieve the text between parentheses where all the text was on a single line. Now I have this case:

(aop)
(abc
d)

This time, the open parenthesis can be on one line and the close parenthesis on another line, so:

(abc
d)

also counts as text between the delimiters ‘( )‘ and I need to print it as

abc
d

EDIT:
In response to possible confusions of my question, let me clarify a little. Basically, I need to print text between delimiters which could span multiple lines.

for example I have this text in my file:

randomtext(1234
567) randomtext
randomtext(abc)randomtext

Now I want Sed to pick out text between the delimiter “(” and “)”. So the output would be:

1234
567
abc

Notice that the left and right brackets are not on the same line but they still count as a delimiter for 1234 567, so I need to print that part of the text. (note, I only want the text between the first pair of delimiters).

Any help would be appreciated.

Answer 1

Ah! another tricky sed puzzle 🙂

I believe this code will work for your problem:

sed -n '/(/,/)/{:a; $!N; /)/!{$!ba}; s/.*(\([^)]*\)).*/\1/p}' file

OUTPUT

For the provided input it produced:

1234
567
abc

Explanation:

• -n suppresses the regular sed output
• /(/,/)/ is for range selection between ( and )
• :a is for marking a label a
• $!N means append the next line of input into the current pattern space
• /)/! means do some actions if ) is not matched in current pattern space
• /)/!${!ba} means go to label a if ) is not matched in current pattern space
• s/.*(\([^)]*\)).*/\1/ means replace content between ( and ) by just the content thus stripping out parenthesis
• \1 is for back reference of group 1 i.e. text between \( and \)
• p is for printing the replaced content