String to code?

ruby-talk
1

is it possible to get user input, and put that in as a code. like lets
say i ask for command and the user types types something like twice 3
which would refer to to a method twice n??

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2

Pavel Pvl wrote:

is it possible to get user input, and put that in as a code. like lets
say i ask for command and the user types types something like twice 3
which would refer to to a method twice n??

Well, you can certainly use the eval method, which just executes a string as Ruby code, but there is some risk involved. You probably wouldn't want to allow somebody to type

system('del *.*')

for example.

Unless you're very smart and very careful (like _why: http://tryruby.hobix.com/\) you shouldn't allow the user to type in real Ruby code.

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RMagick: http://rmagick.rubyforge.org/

3

yes i know that, and in the actual app im not going to have that. just
for my self.

thank you very much

I love ruby

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4

Tim Hunter wrote:

Well, you can certainly use the eval method, which just executes a
string as Ruby code, but there is some risk involved. You probably
wouldn't want to allow somebody to type

system('del *.*')

for example.

Why not? I mean the user wouldn't type something like this without knowing
what it means/does. So if he wants to delete all his files why not let him?

Of course it's different when the script runs on another system than the user
is on, but since the op mentioned getting input from the user via gets, I
assume this is not the case here.

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