UNIX for Dummies Questions & Answers

I need the get the difference between 2 files and the result, I need to output it to an other file
file1
1
1
2
file2
1
1
2
3
Result....File3=3
used diff file1 file2 > file3 ( not working as expected)..Exact requirement..I have 2 flatfiles to compare and load only the difference in a table.

Please suggest...Thanks

Are they always going to be in order like this?

---------- Post updated at 02:31 PM ---------- Previous update was at 02:26 PM ----------

Code:

$ diff a b
3a4
> 3
$ diff a b | grep "^>" | sed 's/^> //'
3
$

Thanks for the prompt reply... These are log files actually..So i believe while using diff one has to sort data first..But i would try this and update..

---------- Post updated at 05:08 AM ---------- Previous update was at 01:24 AM ----------

Warning: missing newline at end of file testfile1.log
Warning: missing newline at end of file testfile2.log
2
3


Thats is what gets displayed..Also, the result shud go to a new file..

Please suggest

Maybe this is what you mean?

Code:

cat testfile1.log testfile2.log | sort | uniq -u > mydifferences.log

try very easy:

Code:

 
diff file1 file2 | tail +2 | cut -d">" -f2

@GERMANICO - I'm afraid that your code does not work. Try running it with more than one difference or records containing spaces. Any approach using "diff" will be very difficult to implement.

@win4luv
If you need to know which file contained the difference it is better to sort each file and the run the unix "comm" command twice with different parameters on the sorted files.
One reason you might want the "comm" approach is could be if you need to distinguish deleted records from new records.

Methyl: your idea did not fetch me the required result..The result what i got is

2
21
3

Can you please let me know abt the sort thing which you are talking about?

Appreciate your help.