Bug #7899: Add feature similar to: perl use warnings

• Status: Closed
• Assignee: -
• Target version: -
• ruby -v: 1.9.3p385

[shevegen (Robert A. Heiler)]

shevy: It would be nice ruby had a way to enable warnings within the code - like perl's use warnings;

Hi,

Background to this is that maasha had problems with shebang, /usr/bin/env and "ruby -w" as part of the shebangs.

He was able to workaround this by setting RUBYOPT:

shevy: I think the conclusion is that one needs to set: export RUBYOPT=-w

A bit background is here:

http://stackoverflow.com/questions/4303128/how-to-use-multiple-arguments-with-a-shebang-i-e

Now one suggestion is to set $VERBOSE to 2 or true. But I am not sure whether this is the
best or most elegant solution.

Could there be a way to enable and disable warnings globally within a .rb script?

Kernel.enable_warnings
Kernel.disable_warnings

Something like that?

Then users could specifically choose to ignore certain warnings, if they want to (like during development when they dont care about all warnings in every .rb file of a project).

[drbrain (Eric Hodel)]

• Category set to core
• Status changed from Open to Closed
• Priority changed from 3 to Normal

Use $VERBOSE or $-w:

$ cat test.rb
"".gsub /x/, ''
$ ruby19 -wv test.rb
ruby 1.9.3p374 (2013-01-15 revision 38858) [x86_64-darwin12.2.1]
test.rb:1: warning: ambiguous first argument; put parentheses or even spaces

$ cat test.rb
$VERBOSE = true
"".gsub /x/, ''
$ ruby19 -v test.rb
ruby 1.9.3p374 (2013-01-15 revision 38858) [x86_64-darwin12.2.1]
test.rb:2: warning: ambiguous first argument; put parentheses or even spaces

$ cat test.rb
$-w = true
"".gsub /x/, ''
$ ruby19 -v test.rb
ruby 1.9.3p374 (2013-01-15 revision 38858) [x86_64-darwin12.2.1]
test.rb:2: warning: ambiguous first argument; put parentheses or even spaces

I will update documentation in doc/globals.rdoc to better describe the behavior of these two globals.