I am clearly missing something WRT 'require'. I have a program file
(test1) which requires another file (test1a). My content, etc. is shown
below. Why doesn't running test1 produce, 'Hello, world!' as output?
Thanks for any input.
... doug
$ ls
test1 test1a.rb
$ cat test1a.rb
var1='Hello, world!'
$ cat test1
#!/usr/bin/ruby
require './test1a.rb'
puts(var1)
$ ./test1
./test1:4: undefined local variable or method `var1' for main:Object
(NameError)
$
···
--
Posted via http://www.ruby-forum.com/.
Try this instead:
# test1a.rb
VAR_ONE = "Hello, world!"
#test1
#!/usr/bin/env ruby
require './test1a'
puts VAR_ONE
$./test1
#=> Hello, world!
This is because Kernel#require, and also, Kernel#load will never leak
local variables into the global namespace.
Kernel#require and #load will however leak constants, and ofcourse
globals, but Kernel#load will wrap the source in an anonymous module
preventing global namespace leaking if you pass 'true' as the second
argument (ie: load('./test1a.rb', true) should result in a NameError
"uninitialized constant"; just make sure you include the '.rb' with
load)
···
On Wed, Jan 18, 2012 at 6:45 PM, Doug Jolley <ddjolley@gmail.com> wrote:
I am clearly missing something WRT 'require'. I have a program file
(test1) which requires another file (test1a). My content, etc. is shown
below. Why doesn't running test1 produce, 'Hello, world!' as output?
Thanks for any input.
\.\.\. doug
$ ls
test1 test1a.rb
$ cat test1a.rb
var1='Hello, world!'
$ cat test1
#!/usr/bin/ruby
require './test1a.rb'
puts(var1)
$ ./test1
./test1:4: undefined local variable or method `var1' for main:Object
(NameError)
$
--
Posted via http://www.ruby-forum.com/\.
var1 is not a global variable, but is instead scoped only to the content
of test1a.rb. If you want to output it from test1 then you would need to
declare it as:
$var1='Hello, world!'
The $ makes it global.
···
On 01/18/2012 06:45 PM, Doug Jolley wrote:
I am clearly missing something WRT 'require'. I have a program file
(test1) which requires another file (test1a). My content, etc. is shown
below. Why doesn't running test1 produce, 'Hello, world!' as output?
Thanks for any input.
... doug
$ ls
test1 test1a.rb
$ cat test1a.rb
var1='Hello, world!'
$ cat test1
#!/usr/bin/ruby
require './test1a.rb'
puts(var1)
$ ./test1
./test1:4: undefined local variable or method `var1' for main:Object
(NameError)
$
--
Darryl L. Pierce <mcpierce@gmail.com>
http://mcpierce.multiply.com/
"What do you care what people think, Mr. Feynman?"
OMG! I researched many posts and articles relating to the topic of
'require' before posting here. None of them mentioned anything about
this aspect of 'require'. Everything I read led me to believe that when
I 'require' a file, the contents of the file is inserted into the source
code at that point as though it had simply been typed into the fi code
directly. Now I don't know if there is a way to do that (i.e., simply
"include" a the contents of a file in the source code). I was a little
confused about what you were trying to tell me about 'load'; but, I
don't think you were telling me that it would accomplish that purpose.
It would be nice to know if there is any way to accomplish this
objective.
This is a total game changer for me. I'm going to have to return to the
drawing board and access whether (in light of this new knowledge) there
is a better way for me to accomplish what I am trying to accomplish. I
may well be back for additional help. However, I think you have fully
clarified this particular issue. Thanks for the input.
... doug
···
--
Posted via http://www.ruby-forum.com/.