current community

your communities

more stack exchange communities

Stack Exchange
tour help
Take the 2-minute tour ×
Unix & Linux Stack Exchange is a question and answer site for users of Linux, FreeBSD and other Un*x-like operating systems.. It's 100% free, no registration required.
up vote 2 down vote favorite

Is there a way to format the following output so that only lines 1 and 4 print out? It would be best if the first line and fourth line could come out on the same line like this:

sw pool test(no bracket)status up

Example command and output:

  • command:

    show server pool

  • output:

    sw pool test {
members 1
ip_addr 200.200.200.111
status up

Desired output formatting (note that the curly bracket that was at the end of line 1 should be removed):

sw pool test status up

How can I get this output, preferably using awk?

share|improve this question

1 Answer 1

up vote 2 down vote

Using awk

This prints the first line without { and the fourth line:

$ show server pool | awk 'NR==1{sub(/{/, ""); printf "%s",$0} NR==4'
sw pool test status up

How it works

  • NR==1{sub(/{/, ""); printf "%s",$0}

    The condition NR==1 selects the first line. For this line, the { is removed with the sub command and then the line is printed using printf (without a trailing newline).

  • NR==4

    The condition NR==4 selects the fourth line. Since no action is specified for this condition, awk does the default action which is. just as we want, to print the line.

Using sed

The same thing is possible with sed:

$ show server pool | sed 'h;N;N;x;N; s/{\n//'
sw pool test status up

How it works

  • h

    This saves the first line in the hold space.

  • N;N

    This reads in lines 2 and 3.

  • x

    This swaps the hold and pattern space. This puts line 1 back in the pattern space.

  • N

    This reads in the next line, line 4, into the pattern space, appending it to line 1.

  • s/{\n//

    This removes the brace and newline from the end of line 1 so that line 1 and line 4 are now merged with brace removed. This is what is printed.

share|improve this answer
    
That's great! I just tried and ran into a few unexpected snags but your tutorial was perfect. I will post one more question to maybe handle the snags I ran into. Thank you. –  jogle900 Mar 31 at 3:13

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.