From: Rob Biedenharn <Rob@...>
Date: 2009-03-10T23:15:46+09:00
Subject: Re: fized size record from a string


On Mar 10, 2009, at 9:53 AM, lucac81 wrote:

> Hello, I'm new to Ruby, and I'm learning it with a project that also
> involves rails...
> I'm stuck with an apparently simple problem, I receive from a form a
> String and I need to extend it to a fixed char number (it must be 16
> chars with eventual trailing spaces)
> I've tought to convert it to an array, it's easy but I don't know how
> to extend it to the needed size.
> Also I could add spaces to the string, but the again how can i control
> how many I need to add?
> Any hint on how I could do that?
> Thank you very much
>

irb> str = "too short"
=> "too short"
irb> lng = "this one is big enough"
=> "this one is big enough"

With Kernel#sprintf (which String#% calls)
irb> "%-16.16s"%str
=> "too short       "
irb> "%-16.16s"%lng
=> "this one is big "

With String#ljust
irb> str.ljust(16)
=> "too short       "
irb> lng.ljust(16)
=> "this one is big enough"

With String#[] (not what you want for short ones)
irb> str[0,16]
=> "too short"
irb> lng[0,16]
=> "this one is big "

-Rob

Rob Biedenharn		http://agileconsultingllc.com
Rob@AgileConsultingLLC.com