How do you search for a specific string?

[andreiraduta]

Hello,

Is there any way to search for a number which contains exactly 13 characters and starts with either 1 or 2 ?

Another question: say i have a list of names. Can i search a document to see if there are any names from the previous link present in document?

Thank you

[richgalloway]

The first question can be solved with regex. For example, the search looks for a 1 or 2 followed by 12 digits.

index=foo | regex "[12]\d{12}" | ...

The second question is unclear. Could you add some detail?