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How to get next 3 lines after regex?

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# 15  
Old 10-02-2013
Quote:
Originally Posted by Scrutinizer
I know what POSIX says ...
Obviously, I did not (but now do). Somehow I had internalized the semicolon before the right-brace as POSIX instead of merely historical practice.

Regards,
Alister
# 16  
Old 10-02-2013
In the rationale section for sed there is also this :

Quote:
Historically, the sed ! and } editing commands did not permit multiple commands on a single line using a <semicolon> as a command delimiter. Implementations are permitted, but not required, to support this extension.
I find that on POSIX compliant systems the semicolon before closing brace seems to always work with sed implementations.
Last edited by Scrutinizer; 10-02-2013 at 05:00 PM..
These 3 Users Gave Thanks to Scrutinizer For This Post:
alister CarloM disedorgue
# 17  
Old 10-02-2013
Quote:
Originally Posted by Scrutinizer
I know what POSIX says, but FWIW on Solaris this works:
Code:
sed -n '/client508/{p;n;p;n;p;}' file

as alister suggested...
Interesting...
I try to write a doc on sed (in french because my english is really very bad Smilie ), and i want describe the best practice.
Quote:
Originally Posted by Scrutinizer
and so does:
Code:
sed -n '/client508/{N;N;p;}' file

Lines will not print if pattern found in last or second last line of file.

Otherwise, sed solution is not the best solution for this problem because we can't chose the number line easily.

Regards.
# 18  
Old 10-02-2013
Quote:
Originally Posted by disedorgue
Lines will not print if pattern found in last or second last line of file.
If those boundary conditions are a concern:
Code:
sed -n '/client508/{$!N; $!N; p;}' file

Regards,
Alister
This User Gave Thanks to alister For This Post:
disedorgue
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