script to match statement from a file

All,

I am trying to write a script which will match the statement from one log file and then proceed for other commands mention in the script.

for my application, backup is schedule to run every day at particular time and creats a log file "/var/adm/backuplog".
if backup completes then last line of this log file will be as below if backup completes on 19th aug
"08/19/2011 11:57:53 Backup has been completed."

this log file is incrimental file, so we can find "Backup has been completed" statement multiple times but with 19th date only one.

Now I want to write a script to check backup completed or not and my require file has been backedup or not. this script will match the last line with current date from the backuplog file. if this script finds that last line says "Backup has been completed" with current date then it will proceed further to check other commands or it will send mail saying that "Either backup has been failed or it is still running"

Could any one please help me, how to write this script?

Thanks,
Anshu

I'm confused. Wouldn't it be better to make the backup system not say "backup completed" if it didn't actually complete?

Actually there are lots of file which is schedule to be backedup through backup script. backup script is written in suhch manner that if any any file is being used or open then backup script will escape that file and will move for another file. if backup script touches all the files then in log file at last line we can find entry "backup has been completed" and those file which has not been backedup we can find one entry "not backedup" or "aborted".