Bug #6723


Global variable scoping problem.

Added by iblue (Markus Fenske) almost 10 years ago. Updated almost 10 years ago.

Target version:
ruby -v:


This issue exists from 1.8 to ruby-head.

See the following example:

def foobar
puts $1.inspect

puts $1.inspect
puts global_variables.inspect

This demonstrates that $1 does not behave like a global variable. However it's listed by Kernel.global_variables as a global variable. And it's named like a global variable.

This leads to some confusion sometimes. See for example

It may not be a good idea to fix this inconsistent naming, because it may break severaly things. However the fact that $1 and friends are not global variables should be clearly documented. And by the way: Ruby != Perl.

Or maybe make $1 a real global variable?

Updated by ko1 (Koichi Sasada) almost 10 years ago

  • Target version set to 2.0.0
  • Category set to core
  • Assignee set to matz (Yukihiro Matsumoto)

Updated by nobu (Nobuyoshi Nakada) almost 10 years ago

  • Category changed from core to doc
  • Status changed from Open to Assigned
  • Assignee changed from matz (Yukihiro Matsumoto) to drbrain (Eric Hodel)
  • ruby -v changed from ruby 1.9.3p194 to -
Actions #3

Updated by drbrain (Eric Hodel) almost 10 years ago

  • Status changed from Assigned to Closed
  • % Done changed from 0 to 100

This issue was solved with changeset r36526.
Markus, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

  • re.c (rb_reg_s_last_match): Update $~ to reference Regexp
    documentation about "special global variables". [Bug #6723]

Updated by drbrain (Eric Hodel) almost 10 years ago

These are described as "Special global variables" and are described as "thread-local and method-local" in the Regexp documentation. I updated a reference to them in re.c, but the existing documentation should be sufficient.


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