NoMethodError: undefined method `scanf' for main:Object

Hi,

I’m trying to use scanf(), but no luck:

$ ruby --version
ruby 1.8.6 (2007-06-07 patchlevel 36) [i486-linux]
$ uname -a
Linux zrbite 2.6.21-2-686 #1 SMP Wed Jul 11 03:53:02 UTC 2007 i686 GNU/
Linux
$ irb
irb(main):001:0> w=scanf("%s")
NoMethodError: undefined method `scanf’ for main:Object
from (irb):1
irb(main):002:0>

Trying to call $stdin.scanf() does not help either (NoMethodError).
What I’m missing?

Cheers,
Alex

Hi –

On Sun, 16 Sep 2007, Alex S. wrote:

irb(main):001:0> w=scanf("%s")
NoMethodError: undefined method `scanf’ for main:Object
from (irb):1
irb(main):002:0>

Trying to call $stdin.scanf() does not help either (NoMethodError).
What I’m missing?

You have to require it:

irb(main):001:0> require ‘scanf’
=> true
irb(main):002:0> a = scanf("%s")
abc
=> [“abc”]
irb(main):003:0> a
=> [“abc”]

David

Hi –

On Sun, 16 Sep 2007, Bil K. wrote:

$ ri scanf
(no description…)

But the original project examples at

http://www.rubyhacker.com/code/scanf/

might get you going…

That version is obsolete; it’s best to use the one that ships with
Ruby. You have to require it, though – it’s standard library rather
than core.

require ‘scanf’
p “abc 123”.scanf("%s%d") => [“abc”, 123]

There’s considerable documentation in the source file, but it’s not in
rdoc form. It’s on my to-do list…

David

Alex S. wrote:

Hi,

Hi.

Trying to call $stdin.scanf() does not help either (NoMethodError).
What I’m missing?

I don’t know, but the ri docs sure are sparse for ruby 1.8.6
(2007-03-13):

$ ri scanf
More than one method matched your request. You can refine
your search by asking for information on one of:

   IO#block_scanf, IO#scanf, Kernel#scanf, String#block_scanf,
   String#scanf

$ ri Kernel.scanf

Kernel#scanf
scanf(fs,&b)

   (no description...)

But the original project examples at

http://www.rubyhacker.com/code/scanf/

might get you going…

Regards,

On Sep 16, 3:15 pm, [email protected] wrote:

require ‘scanf’
p “abc 123”.scanf("%s%d") => [“abc”, 123]

There’s considerable documentation in the source file, but it’s not in
rdoc form. It’s on my to-do list…

Thanks – this resolves my issue. Seems like the docs on scanf are
simply outdated. :slight_smile:

Alex

This forum is not affiliated to the Ruby language, Ruby on Rails framework, nor any Ruby applications discussed here.

| Privacy Policy | Terms of Service | Remote Ruby Jobs