Ruby equivalent to Python's help()?

Question

When working in interactive python, I tend to rely on the builtin help() function to tell me what something expects and/or returns, and print out any documentation that might help me. Is there a ruby equivalent to this function?

EDIT I'm looking for something I could use in irb. For example in interactive python I could type

>>> help(1)

which would then print

Help on int object:

class int(object) | int(x[, base]) -> integer | |

Convert a string or number to an integer, if possible. A ...

Answer 1

Try using ri from the command line.

It takes a class name, method, or module as an argument, and gives you appropriate documentation. Many popular gems come with this form of documentation, as well, so it should typically work even beyond the scope of core Ruby modules.

Answer 2

It's definitely a poor cousin to ipython's help (and one of the main features I miss after moving to ruby), but you can also use ri from within irb. I'd recommend the wirble gem as an easy way to set this up.

Answer 3

There's supposed to be irb_help. But like mentioned in that post, it's broken in my ruby install as well.