CODEWITHSUNDEEP
bashawk
X.LINK
X.LINK

Reputation: 131

How to select two specific lines with awk?

/!\ The question is basically solved, see my own answer below for more details and a subsidiary question /!\

I'm trying to add two lines based on specific word, but all I could find is adding everything after some pattern: How to select lines between two marker patterns which may occur multiple times with awk/sed

Which is not what I'm looking after.

Consider the following output:

aji 1
bsk 2
cmq 3
doh 4
enr 5
fwp 6
gzx 7

What I'm trying to get is something like cmq + fwp, which output should be:

9

I do know how to add values, but I'm missing the select line containing cmq, then select line containing fwp part.

So, is there a way awk could strictly select two specific lines independently (then add them) ?

Edit:

As far as I know, matching words is awk '/cmq/', but I need to do that for let's say "fwp" too so I can add them.

Upvotes: 1

Views: 346

Answers (2)

X.LINK
X.LINK

Reputation: 131

Now, for a more generic way this time -which even works for subtracting-:

awk '/cmq/{x=$2} /fwp/{y=$2} END {print x+y}'

Where:

awk '          # Invoking awk and its instructions
/cmq/{x=$2}    # Select line with "cmq", then set its value to x. Both must be tied
/fwp/{y=$2}    # Select line with "fwp", then set its value to y. Both must be tied
END            # Ends pattern matching/creation
{print x+y}    # Print the calculated result
'              # Ending awk's instructions

Unfortuanately, two variables are used (x and y).

So, I'm still interested on finding how to do it without any variable, or only one at the very most.

 

I do have a single-variable way for summing:

awk '/cmq|fwp/ {x+=$2} END {print x}'

But doing this for subtracting:

awk '/cmq|fwp/ {x-=$2} END {print x}'

doesn't work.

As an subsidiary question, anyone knows to achieve such subtracting without or with only one variable ?

Upvotes: 0

Akshay Hegde
Akshay Hegde

Reputation: 16997

$ awk '$1 ~ /^(cmq|fwp)$/{sum+=$2} END { print sum}'  infile

Explanation:

awk '$1 ~ /^(cmq|fwp)$/{     # look for the match in first field
       sum+=$2               # sum up 2nd field ($2) value,where sum is variable
     }
     END{                    # at the end
       print sum             # print variable sum
     }' infile

Test Results:

$ cat infile
aji 1
bsk 2
cmq 3
doh 4
enr 5
fwp 6
gzx 7

$ awk '$1 ~ /^(cmq|fwp)$/{sum+=$2} END { print sum}'  infile
9

Upvotes: 6

Related Questions