i need to run a query where it will read all the name from my text file and pull out the age from informix table according to the names in my text file.The names are the primary key in my database.

Is there a way i can get this through a script?

Hope this is what you are looking for:

create temp table names (name varchar(20));
load from names.txt insert into names;
select a.name, a.age
from <your table> a, names b
where a.name = b.name;