I have two text file "account.txt" and "customer.txt"

**account.txt**

876251251
716126181
888281211
666615211
787878787
111212134

**customer.txt**

876251251
716126181
792342108
792332668
666615211
760332429
791952441
676702288

I need to compare "account.txt" with "customer.txt".

• All account numbers from account.txt should be present in customer.txt file and if customer.txt is missing any "account number" then we should print out all those account numbers which are missing in customer.txt.


• And also all those extra customer numbers in customer.txt that are not present in account.txt file, I want to print that as well.

Output should be:

Missing Account Number:
888281211
787878787
111212134

Extra Customer Number:
792342108
792332668
760332429
791952441
676702288

Is this possible to do in linux? I started off like this but it only does the first case I want, not the second one? Also I need to print the output in the above format.

comm -23 account.txt customer.txt

Note: It could be possible that there are some strings or empty lines in those files so we need to discard that in the comparison if we see any. We only need to compare valid numbers.

Another simple option would be to use comm; it just needs sorted input, so give it clean input by filtering for "valid account numbers" (the whole line consists only of 9 digits), then pipe to sort before redirecting to a new file:

grep -Ex '[[:digit:]]9' account.txt | sort > account.txt.sorted
grep -Ex '[[:digit:]]9' customer.txt | sort > customer.txt.sorted

... then use comm as you indicated:

 echo 'Missing Account Number:'; comm -23 account.txt.sorted customer.txt.sorted; 

 echo 'Extra Customer Number:'; comm -13 account.txt.sorted customer.txt.sorted; 

Given sample inputs of:

account.txt

garbage
876251251
716126181
888281211
666615211
666615211extra
787878787
111212134
extra

customer.txt

garbage
876251251
876251251extra
716126181
792342108
792332668
666615211
760332429
791952441
676702288
junk

The resultant output is:

Missing Account Number:
111212134
787878787
888281211

Extra Customer Number:
676702288
760332429
791952441
792332668
792342108

Yes, it is possible, maybe easiest with diff.

$ diff account.txt customer.txt
1c1
< **account.txt**
---
> **customer.txt**
5c5,6
< 888281211
---
> 792342108
> 792332668
7,8c8,10
< 787878787
< 111212134
---
> 760332429
> 791952441
> 676702288

$ diff account.txt customer.txt|grep '^<'
< **account.txt**
< 888281211
< 787878787
< 111212134

$ diff account.txt customer.txt|grep '^>'
> **customer.txt**
> 792342108
> 792332668
> 760332429
> 791952441
> 676702288

The following shellscript diff-script is more polished.

#!/bin/bash

# assuming 9-digit account and customer numbers

sort account.txt | uniq > account.srt
sort customer.txt | uniq > customer.srt

diff account.srt customer.srt > diff.txt

echo 'only in account.srt:' > result.txt
< diff.txt grep -E '^< [0-9]9$' | sed s'/^< //' >> result.txt

echo 'only in customer.srt:' >> result.txt
< diff.txt grep -E '^> [0-9]9$' | sed s'/^> //' >> result.txt

echo "The result is in the file 'result.txt'"
echo "You can read it with 'less result.txt'"

Demo example,

$ ./diff-script
The result is in the file 'result.txt'
You can read it with 'less result.txt'

$ cat result.txt 
only in account.srt:
111212134
787878787
888281211
only in customer.srt:
676702288
760332429
791952441
792332668
792342108

For this job i would choose awk. Bellow code runs only for valid data of 9 numbers in the row. Empty lines, lines with numbers more or less than 9, and lines with letters are ignored.

$ cat account
876251251

716126181
888281211
asdferfggggg
666615211
787878787
123456789123
111212134

$ cat customer
876251251
716126181
eeeeeeeee
792342108
792332668
666615211
760332429

791952441
676702288

$ awk '/^[0-9]9$/a[$0]++;b[$0]="found only in " FILENAMEENDfor (i in a) if (a[i]==1) print i,b[i]' account customer |sort -k2
111212134 found only in account
787878787 found only in account
888281211 found only in account
676702288 found only in customer
760332429 found only in customer
791952441 found only in customer
792332668 found only in customer
792342108 found only in customer