Workaround for "conflict" between ARGV and gets?

[RichardOnRails]

gets looks to ARGV, if populated, for its source of data. That is its
documented behavior.

I want to:
1) use ARGV to point to a directory I want to process and
2) use gets to inquire whether the user wants the program to proceed
with that directory.

I thought I might be able to reset ARGV to an empty array after I
saved its content, but that doesn't work. Is there a way around this.

The following code never pauses to allow the user to enter yes/no, as
I intended it to. Is there a workaround?

=== Code ==
puts "ARGV = %s" % ARGV.join(", ")
argv = ARGV[0] # Save ARGV's content
ARGV = [] # Reset ARGV to an empty array
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp # doesn't go to STDIN !!!
puts case response
when /^yes$/i; "Deleting"
when /^no$/i; "Quiting"
else; "Huh?"
end
puts "EOJ"

puts "EOJ"

 

[Ryan Davis]

gets looks to ARGV, if populated, for its source of data. That is its
documented behavior.

I want to:
1) use ARGV to point to a directory I want to process and
2) use gets to inquire whether the user wants the program to proceed
with that directory.

I thought I might be able to reset ARGV to an empty array after I
saved its content, but that doesn't work. Is there a way around this.

The following code never pauses to allow the user to enter yes/no, as
I intended it to. Is there a workaround?

=== Code ==
puts "ARGV = %s" % ARGV.join(", ")
argv = ARGV[0] # Save ARGV's content
ARGV = [] # Reset ARGV to an empty array
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp # doesn't go to STDIN !!!

ri IO.gets
ri Kernel.gets

 

[Walton Hoops]

gets looks to ARGV, if populated, for its source of data. That is its
documented behavior.

I want to:
1) use ARGV to point to a directory I want to process and
2) use gets to inquire whether the user wants the program to proceed
with that directory.

I thought I might be able to reset ARGV to an empty array after I
saved its content, but that doesn't work. Is there a way around this.

The following code never pauses to allow the user to enter yes/no, as
I intended it to. Is there a workaround?

=== Code ==
puts "ARGV = %s" % ARGV.join(", ")
argv = ARGV[0] # Save ARGV's content
ARGV = [] # Reset ARGV to an empty array
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp # doesn't go to STDIN !!!

Change this line to 'STDIN.gets.chomp'. Finit!

puts case response
when /^yes$/i; "Deleting"
when /^no$/i; "Quiting"
else; "Huh?"
end
puts "EOJ"

puts "EOJ"

Best,
Walton

 

[Jeff Peng]

在 2010-02-01一的 13:15 +0900，RichardOnRails写é“：

gets looks to ARGV, if populated, for its source of data. That is its
documented behavior.

I changed the script to:

dir=ARGV[0]
ARGV.clear
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp # doesn't go to STDIN !!!
puts case response
when /^yes$/i; "Deleting"
when /^no$/i; "Quiting"
else; "Huh?"
end
puts "EOJ"


It works fine for me.

$ ruby pause.rb 323
Delete indicated item [yes, no]
yes
Deleting
EOJ

 

[RichardOnRails]

在 2010-02-01一的 13:15 +0900，RichardOnRails写é“：

gets looks to ARGV, if populated, for its source of data.  That isits
documented behavior.

I changed the script to:

dir=ARGV[0]
ARGV.clear
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp   # doesn't go to STDIN !!!
puts case response
  when /^yes$/i; "Deleting"
  when /^no$/i; "Quiting"
  else; "Huh?"
  end
puts "EOJ"

It works fine for me.

$ ruby pause.rb 323
Delete indicated item [yes, no]
yes
Deleting
EOJ

--
Jeff Peng
Email: (e-mail address removed)
Skype: compuperson

ARGV.clear

Excellent. My heavy-handed method pales in light of your solution.
Many thanks, Jeff
-
Richard

 

[RichardOnRails]

gets looks to ARGV, if populated, for its source of data.  That is its
documented behavior.

I want to:
1)  use ARGV to point to a directory I want to process and
2)  use gets to inquire whether the user wants the program to proceed
with that directory.

I thought I might be able to reset ARGV to an empty array after I
saved its content, but that doesn't work.  Is there a way around this..

The following code never pauses to allow the user to enter yes/no, as
I intended it to.  Is there a workaround?

=== Code ==
puts "ARGV = %s" % ARGV.join(", ")
argv = ARGV[0]                     # Save ARGV's content
ARGV = []                          # Reset ARGV to an empty array
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp      # doesn't go to STDIN !!!

Change this line to 'STDIN.gets.chomp'.  Finit!

puts case response
   when /^yes$/i; "Deleting"
   when /^no$/i; "Quiting"
   else; "Huh?"
   end
puts "EOJ"

puts "EOJ"
Best,
Walton

STDIN.gets.chomp

Very cool: Just tell gets I want the STDIN flavor!!
Many thanks, Walton
-
Richard

 

[RichardOnRails]

gets looks to ARGV, if populated, for its source of data.  That is its
documented behavior.

I want to:
1)  use ARGV to point to a directory I want to process and
2)  use gets to inquire whether the user wants the program to proceed
with that directory.

I thought I might be able to reset ARGV to an empty array after I
saved its content, but that doesn't work.  Is there a way around this..

The following code never pauses to allow the user to enter yes/no, as
I intended it to.  Is there a workaround?

=== Code ==
puts "ARGV = %s" % ARGV.join(", ")
argv = ARGV[0]                     # Save ARGV's content
ARGV = []                          # Reset ARGV to an empty array
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp      # doesn't go to STDIN !!!

ri IO.gets
ri Kernel.gets

I see, Ryan. What I should have done to understand the problem fully
was:

puts gets.class # => String

which makes it clear why I didn't get the 'native' versions you
pointed out. I had checked in http://www.ruby-doc.org/core/ but made
two stupid mistakes: I failed to notice Kernel in the middle column
and gets (Kernel) in the right-hand column. And I never thought of
IO, nor noted gets (IO) in the right-hand column.

It all begs the question: When will I learn enough Ruby to program
without you guys

Best wishes,
Richard

 

[Marnen Laibow-Koser]

with that directory.
ARGV = [] � � � � � � � � � � � � �# Reset ARGV to an empty array
puts "Delete indicated item [yes, no]"
STDOUT.flush
response = gets.chomp � � �# doesn't go to STDIN !!!

ri IO.gets
ri Kernel.gets

I see, Ryan. What I should have done to understand the problem fully
was:

puts gets.class # => String

which makes it clear why I didn't get the 'native' versions you
pointed out.

No it doesn't. All it tells you is that gets returns a String.

[...]

It all begs the question: When will I learn enough Ruby to program
without you guys

That depends on you. Good luck!

Best wishes,
Richard

Best,
-- 
Marnen Laibow-Koser
http://www.marnen.org
(e-mail address removed)

 

[Robert Klemme]

I see, Ryan. =A0What I should have done to understand the problem fully
was:

puts gets.class # =3D> String

which makes it clear why I didn't get the 'native' versions you
pointed out. =A0I had checked in http://www.ruby-doc.org/core/ but made
two stupid mistakes: I failed to notice Kernel in the middle column
and gets (Kernel) in the right-hand column. =A0And I never thought of
IO, nor noted gets (IO) in the right-hand column.

Here's something you can do to find out more about a method:

irb(main):006:0> methodgets)
=3D> #<Method: Object(Kernel)#gets>
irb(main):007:0> methodgets).owner
=3D> Kernel

Then you can do "ri Kernel#gets" and get the docs (or look online at
http://www.ruby-doc.org/ of course).

It all begs the question: =A0When will I learn enough Ruby to program
without you guys

Well, but then you could not have all these nice little chats with us. ;-)

Cheers

robert

--=20
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/