I'm trying to learn Ruby and trying to convert a Perl program at the
same time. I need to prompt a user to enter a number to select a
processing option. In Perl, I did it this way:
I've searched the web and several books, but I haven't found anything
that works. It also seems that my system doesn't recognize "gets". Can
anyone help me out, and maybe post a simple input routine I can look at?
Thanks....
--
Posted via http://www.ruby-forum.com/.
I'm trying to learn Ruby and trying to convert a Perl program at the
same time. I need to prompt a user to enter a number to select a
processing option. In Perl, I did it this way:
If your system isn't recognizing gets, then you've got some other problem that should be fixed before writing much code.
···
On Sep 29, 2007, at 8:28 PM, Peter Vanderhaden wrote:
I'm trying to learn Ruby and trying to convert a Perl program at the
same time. I need to prompt a user to enter a number to select a
processing option. In Perl, I did it this way:
I've searched the web and several books, but I haven't found anything
that works. It also seems that my system doesn't recognize "gets". Can
anyone help me out, and maybe post a simple input routine I can look at?
Thanks....
--
Posted via http://www.ruby-forum.com/\.
Sebastian,
FYI, the reason I'm sending the prompt to STDERR instead of STDOUT is
that I've used reopen to redirect STDOUT to a file. I did that because
I want to write data to a file. I'm new to this, so if there's a better
way to write to the file, I'm all ears
PETERV
Peter Vanderhaden wrote:
···
Sebastian,
My Ruby installation must be corrupt, as it doesn't recognize gets.
When I try your solution, I get the following error message:
D:/scripts/ruby/f0.rb:10:in `gets': Bad file descriptor (Errno::EBADF)
from D:/scripts/ruby/f0.rb:10
I'd assume the best way to correct this would be to reinstall Ruby?
Would you agree?
Thanks,
PETERV
Sebastian Hungerecker wrote:
Peter Vanderhaden wrote:
print STDERR "Enter option: ";
The ruby equivalent of this would be STDERR.print "Enter option: " but
why
STDERR? That hardly looks like an error message to me.
chomp ($option = <STDIN>);
That would be gets.chomp or STDIN.gets.chomp if you want to make
sure that
you read from STDIN.
I've searched the web and several books, but I haven't found anything
that works. It also seems that my system doesn't recognize "gets".
Your system is not supposed to recognize gets. If your ruby does not
recognize
gets, there is something seriously wrong with your ruby installation.
Sebastian,
My Ruby installation must be corrupt, as it doesn't recognize gets.
When I try your solution, I get the following error message:
D:/scripts/ruby/f0.rb:10:in `gets': Bad file descriptor (Errno::EBADF)
from D:/scripts/ruby/f0.rb:10
Well, he doesn't say that he doesn't recognize gets, he says that an error
occured while executing gets.
It should be noted that Kernel#gets will open ARGV[0] as a file and read that
instead of STDIN when ARGV is not empty, which is the most common cause of
errors with gets. So if that's the problem in your case, try using STDIN.gets
instead of Kernel#gets. If that doesn't help, show the code.
I'd assume the best way to correct this would be to reinstall Ruby?
Would you agree?
If your gets is really broken and you're not just using it wrong, then yes.
Sebastian,
FYI, the reason I'm sending the prompt to STDERR instead of STDOUT is
that I've used reopen to redirect STDOUT to a file. I did that because
I want to write data to a file. I'm new to this, so if there's a better
way to write to the file, I'm all ears
PETERV
File.open(filename,'w') do |f|
f.puts "Text that's supposed to go in the file"
puts "Text that's supposed to go to the screen"
f.puts "More text for the file"
STDERR.puts "Error message"
end
Sebastian,
FYI, the reason I'm sending the prompt to STDERR instead of STDOUT is
that I've used reopen to redirect STDOUT to a file. I did that because
I want to write data to a file. I'm new to this, so if there's a better
way to write to the file, I'm all ears
How about:
1)
f = File.new("data.txt", "w")
f.write("hello world\n")
f.close()
2)
f = File.open("data.txt", "w") do |file|
file.puts("goodbye mars")
end
7stud,
Thanks! This is obviously much better than what I was doing! Being new
to this type of language, I really appreciate the help! I do have one
more question for you though. What's the difference between using
file.puts & file.print?
7stud -- wrote:
···
7stud -- wrote:
2)
f = File.open("data.txt", "w") do |file|
file.puts("goodbye mars")
end
Whoops, too slow. And I had some detritus stuck to the front of that
example anyway. It should be:
2)
File.open("data.txt", "w") do |file|
file.puts("goodbye venus")
end
