Monday, April 19, 2010

DIFF utility: Find Differences Between Files

Working as a DBA , you may encounter situations like to compare two files to check whether the contents are same or not.
diff will surely make your life easy.Believe IT or ....

$ diff init.ora init1.ora

Check the output showing the differences in the files:
< sga_max_size=900M
< sga_target=700M
> sga_max_size=800M
> sga_target=600M
> # sort_area_size=0

here, < refer to file1 & > refer to file 2.
And , c stands for change
a stands for append (looks like file 2 has one more line & that is 20 which shows contents "# sort_area_size=0"

There is another tag like d (beside c & a) which stands for delete.

$ diff init.ora init1.ora > change.diff
To convert init.ora to init1.ora, use the "patch" command with the difference report output:
$ patch init.ora change.diff

We can even use "sdiff" utility too.
Ex: $ sdiff init.ora init1.ora

This will show the changes in more readable format.

Note: can also use "diff3" utility to compare differences between three files.

Find Differences Between Directories:

Possible guys!!!!

$ diff /oracle/scripts /u01/oracle/scripts

thanks... have a nice day.