Verify the data type in a file with UNIX function

I am seeking help on this UNIX function, please help. Thanks in advance.

I have a large file, named as 'MyFile'. It was tab-delmited, I am told that each record in column 1 is unique. How would I verify this with UNIX function or command?

Do not post classroom or homework problems in the main forums. Homework and coursework questions can only be posted in this forum under special homework rules.

Please review the rules, which you agreed to when you registered, if you have not already done so.

More-than-likely, posting homework in the main forums has resulting in a forum infraction. If you did not post homework, please explain the company you work for and the nature of the problem you are working on.

If you did post homework in the main forums, please review the guidelines for posting homework and repost.

Thank You.

The UNIX and Linux Forums.