Originally Posted by RudiC

You're taking the scenic route, running multiple awk multiple unneeded times. On top:
- You're reading a line (from where? terminal, I presume?) to no avail - the variable is not used anywhere any more.

I am running my code in ideone.com so Instead of filename i am passing input from stdin.

- You're assigning a variable a to no avail innthe first awk.

I was trying to assign the output to variable a ie matching or mismatch

- You're using that a variable as a constant, independent of the condition you want applied, in the second awk.

- You're using the assignment operator = in lieu of the comparison operator ==.

yes i see = is to assign the value and == is comparison thanks.

- You're not giving awk the right field separator , .

do you mean IFS="," or i should also specify OFS when writing back to file.

Try instead:

Code:

awk -F, '{print $0, NR==1?"c4":($2!=$3?"mis":"")"match"}' OFS=, file
c1,c2,c3,c4
1,a,b,mismatch
1,b,b,match

Originally Posted by Scrutinizer

Hi try something like this:

Code:

awk '{print $0, ($NF==$(NF-1))?"match":"mismatch"}' FS=, OFS=, filename.txt