'gets' has been hijacked

[Pete Elmore]

I was working with a simple script, that unexpectedly broke. The
problem can be reduced to this:

pete@robots:~$ cat t.rb
#!/usr/bin/env ruby
p gets
pete@robots:~$ ./t.rb
asdf
"asdf\n"
pete@robots:~$ ./t.rb nonexistent-file
/t.rb:2:in `gets': No such file or directory - nonexistent-file
(Errno::ENOENT)
from ./t.rb:2

Ah, right, I remember this from the Bad Old Days of Perl: stdin has been
stolen. Is there any way to stop this behavior, like a global I could
set or a flag I could pass to ruby? Couldn't find anything on the man
page or in Pickaxe.

 

[James Edward Gray II]

Yeah, that's what I'm doing. What I was wondering was if there was
something I could do to point Kernel#gets back at stdin.

I'm sure there is. Off the top of my head (untested!):

module Kernel
def gets() $stdin.gets end
end

But why not just ask Ruby for what you really meant in the first
place?

James Edward Gray II

 

[Mark Hubbart]

On Jun 6, 2005, at 2:31 PM, Pete Elmore wrote:
=20
=20
gets() as you're using it calls Kernel.gets(), which basically
amounts to ARGF.gets(). That's very handy for building Unix filters.

expanding on that: ARGF *is* STDIN when there are no files specified:

mark@eMac% ruby -e'p ARGF.fileno =3D=3D STDIN.fileno'
true
mark@eMac% ruby -e'p ARGF.fileno =3D=3D STDIN.fileno' /etc/hosts
false

 

[Pete Elmore]

I'm sure there is. Off the top of my head (untested!):

module Kernel
def gets() $stdin.gets end
end

Ah, thanks. I'll probably just keep using $stdin.gets if there's not a
really clean way.

But why not just ask Ruby for what you really meant in the first
place?

puts always goes to $stdout (well, $defout), so I thought that gets
would read $stdin, or it would be possible to nicely ask it to do so. I
don't mind $stdin.gets, but it seems a little odd. (I realize that I'm
treading dangerously close to POLSland, so I'll stop.

Hope that helps.

I'm always thankful to the community for tolerating my endless stream of
n00b questions.