difference between files (same file)

[bengalliboy]

All,
I am trying to come up with a process of identifying the difference between two files that are extracted from ORACLE.

The issue is, there is no date when file A is extracted. After a week or so, this is file is extracted again. What I want to do , is to identify the deltas. What is being changed and what is new. Get this and discard the old file and use it for my case. The same is done every week.

Thanks in advance!!!

 

[columb]

Some assumptions
1) the file is created in /home/workdir
2) the output file is called output

then

if [ -f /home/workdir/output ]
then
  diff /home/workdir/output* | mail -s "output differences" myuser@myhost
  rm /home/workdir/output.old
  mv /home/workdir/output /home/workdir/output.old
fi

run this from cron at a suitable time

 

[bengalliboy]

Thanks.
Will the diff command identify all the changes in fields on the file? I think it will certainly get the new data.
Say, values in this file:

Key Name Address
1234 Some Name Address1

Changed to:
Key Name Address
1234 Some Name Address2

Again Changed to:
Key Name Address
1234 Name1 Address2

Again I get:
Key Name Address
1234 Name1 Address2


I should be able to get the record 3 times. First time, it is a new record. 2nd and third time , some thing changed. Fourth time it should not come since nothing changed for that record.
TIA

 

[columb]

Are all these changes being reported in the same output file?