Postgresql :i want tro truncate column I have

select * from generale where titolo  ~* 'hp-ux' order by titolo;
      autori       |                                                   titolo                                                    |        casaeditrice        
-------------------+-------------------------------------------------------------------------------------------------------------+----------------------------
 Asghar Ghori      | HP Certified Systems Administrator: Hp-ux 11i V3: Exam Hp0-a01: Training Guide and Adminstrator's Reference | Endeavor Technologies Inc.
 Autori vari       | HP-UX tuning and performance                                                                                | Prentice Hall


The line title is very long for Book Entry Hp Certified...etc,etc
I want to truncate to this

 Asghar Ghori      | HP Certified Systems Administrator:....


The ... are not important i want to truncate column output to max 20 characters,
on oracle i use column titolo format a20 how to do this on postgres?
Thanks
try this

select autori, substring(titolo,1,20) || '...'
from generale where titolo  ~* 'hp-ux' order by titolo;


it truncates your output but doesn't touch the data in the table