I think that you may be looking for, as one way,
ods pdf;
proc sql;
select *
from dictionary.columns
where libname='IN'
;
quit;
ods pdf close;
The dictionary.columns is one way when using Proc Sql to reference the data view SAS maintains with the properties of the variables of all the data sets in all the libraries. The LIBNAME, library name, and MEMNAME, member name i.e. data set name, are stored as all upper case letters so use upper case to find the ones you want.
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