What does this ruby operator mean $?

Question

What does the $? Ruby operator mean?

I know that it is used for system calls and can be used to tell if a system call was successful.

I tried searching for documentation but couldn't find it.

Look in the [English documentation](http://ruby-doc.org/stdlib-2.3.3/libdoc/English/rdoc/English.html) in the STDLIB. — the Tin Man, Dec 15 '16 at 23:22

user229044 · Accepted Answer · 2016-12-15T21:58:57.187

3

There is no $ operator. $ is used to prefix global variables. What you're thinking of as an operator is actually just a bunch of predefined global variables that Ruby provides for you, which happen to have odd names like $! and $:.

See http://ruby-doc.org/docs/ruby-doc-bundle/Manual/man-1.4/variable.html

edited Dec 15 '16 at 21:58

answered Dec 15 '16 at 21:57

user229044

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There's a dupe for that. – Makoto Dec 15 '16 at 21:58
why would you being a moderator answer such question instead of locking it as duplication? :) – Andrey Deineko Dec 15 '16 at 22:01
@AndreyDeineko Because I was unaware of the dupe? – user229044 Dec 15 '16 at 22:01
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Hm, could be. But I doubt there is at least single more or less seasoned SO user (and you are definitely one of those big users) with Ruby background who would not think this was asked before. (downvote's not mine) – Andrey Deineko Dec 15 '16 at 22:03

What does this ruby operator mean $?

1 Answers1