Shell Programming and Scripting

hello,
I have backup directory and if i will delete file then it is going in backup
directory. my concern is if backup have file whoes name is abhi and user
again deletes file with the same name abhi...then i want to maintain both
the files in backup directory.

can you please help me for logic..and script

There is no possibility of having same file names for more than one files in the same directory.

You can go for something like, appending the unique number to the files, or appending the epoch to the file name, like some trackable info by you can be used.

Can you please tell me the script for that...

You'd need a versioning file system. I don't think any Linux system does that (and Wikipedia agrees: Versioning file system - Wikipedia, the free encyclopedia ). It was available (and I guess still is, though who cares) on SCO OSR5 and Novell, but hardly anybody ever used it. The main purpose is to provide undelete.

Assuming you can convince your users, you could use a version control system to keep multiple versions of files, but that's not transparent like a versioning file system.

Or, in your script, when you move the file to the backup directory, append the timestamp to the filename:

Code:

mv $file /path/to/backup/$file_$(date -u +%Y-%m-%dT%H:%M:%SZ)

This will append the current UTC timestamp in proper ISO 8601 notation. And if needed you can make it even more unique using nanoseconds and $RANDOM.

hello
you can say for e.g. attach the time stamp to the file name before deleting it. This will help in maintaining when the file was deleted and also help in determining the uniqueness of the file.
you must already be having the script that is doing the current job for you . Modify the code to attach the time stamps before placing it in the backup directory.
Regards.