[SOLVED] Combine grep output when piping

Issue

I use the following command sipcalc to display information about an IP:

sipcalc 192.16.12.1/16 | grep -E 'Network address|Network mask \(bits\)'

The output is:

Network address     - 192.16.0.0
Network mask (bits) - 16

Is there a way to combine the above output (only the right part), so the output would be:

192.16.0.0/16

I have my own way to do this by separating grep call and then concatenate the result, but I don't think it is a good solution. Can grep or any other commands that can be used to pipe the output like awk in order to obtain the output above?

Solution

grep is not really an ideal tool for doing operations beyond just searching for your expected text. Use awk alone!

awk '/Network address/{ ip = $NF } /Network mask \(bits\)/{ print ip "/" $NF}'

Awk processes records in /pattern/ { action } syntax. So when the first pattern in matched, extract the last field delimited by space $NF i.e. a special variable Awk uses to store the value of last column when delimited by space ( See 7.5.1 Built-in Variables That Control awk)

When the second pattern is matched in a similar way, join that last field with the value stored in ip variable. The + just concatenates the individual strings to produce the desired result.

Answered By - Inian