Function for determining column witdhs in libpq ?

I need to build a create table statement based on the some of the field names I retreive from an existing table. I have
madeuse of the
 
functionalityin Pqftype() but that doesn't help me distiguish between a column ofVARCHAR(20) and a a column of
VARCHAR(8).Is there a function in lipq to do
 
this ?


Thanks

David