Compare line and printing difference

Shell Programming and Scripting
1

Hi,

I want to compare two files and print out their differences
e.g:
t1.txt

a,b,c,d

t2.txt

a,b,c,d,e,f

Output

e,f

Currently I do this long about way

tr ',' '\n' <t1.txt >t1.tmp
tr ',' '\n' <t2.txt >t2.tmp
diff t1.tmp t2.tmp > t12.tmp

I have to this comparison for 100 files, so looking for a cleaner way without doing tr and storing in tmp file

2

Hello Wahi,

Could you please try following and let me know if this helps you.

 awk -F, 'FNR==NR{split($0, A,",");next} {for(i=1;i<=NF;i++){D=$i;for(D in A){delete A}}} END{for(j in A){print A[j]}}' t2 t1

output will be as follows.

e
f

EDIT: Adding a non one-liner form of solution too.

awk -F, 'FNR==NR        {
                                split($0, A,",");
                                next
                        }
                        {       for(i=1;i<=NF;i++)      {
                                                                D=$i;
                                                                for(D in A)     {
                                                                                        delete A
                                                                                }
                                                        }
                        }
         END            {       for(j in A)             {
                                                                print A[j]
                                                        }
                        }
         ' t2 t1

Thanks,
R. Singh

3

Hi Ravinder,

Your solution almost got what I wanted. The only thing is that the code needs to check if the order is same too. I think I missed adding that in my original thread
e.g: t1.txt

a,b

t2.txt

b,a

It should tell that files are different and why

Maybe I should do a cksum first and then if different, check if it is different because of order, different because field name is different or extra field.

4

So, what should be the resulting difference of this input:

a,b,c,d,e,f

and

b,c,d,e,f,a

?