# Warnings? **URL:** \ **Category:** ruby-talk\ **Created:** [29 July 2003 10:16 UTC](https://rubytalk.org/t/warnings/7079 "2003-07-29T10:16:56Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Tim\_Bates](https://avatars.discourse-cdn.com/v4/letter/t/3da27b/32.png) [@Tim\_Bates](https://rubytalk.org/u/Tim_Bates)\ **Post date:** [29 July 2003 10:16 UTC](https://rubytalk.org/t/warnings/7079/1 "2003-07-29T10:16:56Z")
Hi all, I’ve recently got around to reinstating some of my old Ruby apps after a system upgrade, part of which involved an upgrade from 1.6 to 1.8pre3. Some of the libraries used in these apps were written for 1.6, and now they spew out loads of warnings. I seem to remember something about warnings being on by default in a planned future version of Ruby, but I didn’t think it was as soon as 1.8 - however, regardless of whether this is the case or not, how do I turn them off? Remember that it’s not my code, so I’m not about to go through and correct all the warnings. The libraries still function correctly. Tim Bates > **···** > > – > [tim@bates.id.au](mailto:tim@bates.id.au) ---
**Author:** ![Yukihiro\_Matsumoto2](https://avatars.discourse-cdn.com/v4/letter/y/b9e5f3/32.png) [@Yukihiro\_Matsumoto2](https://rubytalk.org/u/Yukihiro_Matsumoto2)\ **Post date:** [29 July 2003 16:00 UTC](https://rubytalk.org/t/warnings/7079/2 "2003-07-29T16:00:21Z")
Hi, > **···** > > In message “Warnings?” on 03/07/29, Tim Bates [tim@bates.id.au](mailto:tim@bates.id.au) writes: > > > I’ve recently got around to reinstating some of my old Ruby apps after a > > system upgrade, part of which involved an upgrade from 1.6 to 1.8pre3. > > Some of the libraries used in these apps were written for 1.6, and now > > they spew out loads of warnings. I seem to remember something about > > warnings being on by default in a planned future version of Ruby, but I > > didn’t think it was as soon as 1.8 - however, regardless of whether this > > is the case or not, how do I turn them off? Remember that it’s not my > > code, so I’m not about to go through and correct all the warnings. The > > libraries still function correctly. > > You’ve inspired me to add a way to stop all warnings. In the near > future release, -W0 stops all warnings. > > ``` > matz. > > ``` ---
**Author:** ![Michael\_Davis1](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@Michael\_Davis1](https://rubytalk.org/u/Michael_Davis1)\ **Post date:** [29 July 2003 19:02 UTC](https://rubytalk.org/t/warnings/7079/3 "2003-07-29T19:02:28Z")
How about a way to trap warnings similar to rescue Exception so we can trap and suppress certain expected warnings? Thanks, Michael Davis Yukihiro Matsumoto wrote: > **···** > > > Hi, > > > > In message “Warnings?” \> on 03/07/29, Tim Bates [tim@bates.id.au](mailto:tim@bates.id.au) writes: > > > > > I’ve recently got around to reinstating some of my old Ruby apps after a > > > system upgrade, part of which involved an upgrade from 1.6 to 1.8pre3. > > > Some of the libraries used in these apps were written for 1.6, and now > > > they spew out loads of warnings. I seem to remember something about > > > warnings being on by default in a planned future version of Ruby, but I > > > didn’t think it was as soon as 1.8 - however, regardless of whether this > > > is the case or not, how do I turn them off? Remember that it’s not my > > > code, so I’m not about to go through and correct all the warnings. The > > > libraries still function correctly. > > > > You’ve inspired me to add a way to stop all warnings. In the near > > future release, -W0 stops all warnings. > > > > ``` > > matz. > > > > ``` ---
**Author:** ![Tim\_Bates](https://avatars.discourse-cdn.com/v4/letter/t/3da27b/32.png) [@Tim\_Bates](https://rubytalk.org/u/Tim_Bates)\ **Post date:** [29 July 2003 22:12 UTC](https://rubytalk.org/t/warnings/7079/4 "2003-07-29T22:12:26Z")
What can I do in the meantime? One of my curses-based apps is practically unuseable, because the database-backed prints lots of warnings every time it does anything. I’d like to have an interim solution. 😉 Tim Bates > **···** > > On Wed, Jul 30, 2003 at 01:00:21AM +0900, Yukihiro Matsumoto wrote: > > > You’ve inspired me to add a way to stop all warnings. In the near > > future release, -W0 stops all warnings. > > – > tim@bates.id.au ---
**Author:** ![Paul\_Brannan](https://avatars.discourse-cdn.com/v4/letter/p/76d3ee/32.png) [@Paul\_Brannan](https://rubytalk.org/u/Paul_Brannan)\ **Post date:** [30 July 2003 13:48 UTC](https://rubytalk.org/t/warnings/7079/5 "2003-07-30T13:48:30Z")
How can this feature be accessed from inside Ruby code? Will it be possible to turn up the warning level? My personal preference would be to always use the highest warning level possible. Paul > **···** > > On Wed, Jul 30, 2003 at 01:00:21AM +0900, Yukihiro Matsumoto wrote: > > > You’ve inspired me to add a way to stop all warnings. In the near > > future release, -W0 stops all warnings. ---
**Author:** ![Yukihiro\_Matsumoto2](https://avatars.discourse-cdn.com/v4/letter/y/b9e5f3/32.png) [@Yukihiro\_Matsumoto2](https://rubytalk.org/u/Yukihiro_Matsumoto2)\ **Post date:** [29 July 2003 19:37 UTC](https://rubytalk.org/t/warnings/7079/6 "2003-07-29T19:37:38Z")
Hi, > **···** > > In message “Re: Warnings?” on 03/07/30, Michael Davis [mdavis@sevasoftware.com](mailto:mdavis@sevasoftware.com) writes: > > > How about a way to trap warnings similar to rescue Exception so we can trap and suppress certain expected warnings? > > Since warning is a mere message, not exit like exceptions, it is more > difficult to catch. You can suppress warning messages by redirecting > $stderr temporarily (although it’s not thread safe). > > ``` > matz. > > ``` ---
**Author:** ![why\_the\_lucky\_stiff1](https://avatars.discourse-cdn.com/v4/letter/w/898d66/32.png) [@why\_the\_lucky\_stiff1](https://rubytalk.org/u/why_the_lucky_stiff1)\ **Post date:** [29 July 2003 22:46 UTC](https://rubytalk.org/t/warnings/7079/7 "2003-07-29T22:46:04Z")
$stderr.close Or: $stderr = File.open( ‘/var/log/tims-ncurses-app.log’, ‘w’ ) \_why > **···** > > On Tuesday 29 July 2003 04:12 pm, Tim Bates wrote: > > > On Wed, Jul 30, 2003 at 01:00:21AM +0900, Yukihiro Matsumoto wrote: > > > > > You’ve inspired me to add a way to stop all warnings. In the near > > > future release, -W0 stops all warnings. > > > > What can I do in the meantime? One of my curses-based apps is > > practically unuseable, because the database-backed prints lots of > > warnings every time it does anything. I’d like to have an interim > > solution. 😉 ---
**Author:** ![Martin\_DeMello1](https://avatars.discourse-cdn.com/v4/letter/m/3be4f8/32.png) [@Martin\_DeMello1](https://rubytalk.org/u/Martin_DeMello1)\ **Post date:** [30 July 2003 06:05 UTC](https://rubytalk.org/t/warnings/7079/8 "2003-07-30T06:05:33Z")
Somewhat far-out, but could AspectR be used to redirect $stderr everytime you entered a database function? martin > **···** > > Tim Bates [tim@bates.id.au](mailto:tim@bates.id.au) wrote: > > > On Wed, Jul 30, 2003 at 01:00:21AM +0900, Yukihiro Matsumoto wrote: > > > > > You’ve inspired me to add a way to stop all warnings. In the near > > > future release, -W0 stops all warnings. > > > > What can I do in the meantime? One of my curses-based apps is > > practically unuseable, because the database-backed prints lots of > > warnings every time it does anything. I’d like to have an interim > > solution. 😉 ---
**Author:** ![Yukihiro\_Matsumoto2](https://avatars.discourse-cdn.com/v4/letter/y/b9e5f3/32.png) [@Yukihiro\_Matsumoto2](https://rubytalk.org/u/Yukihiro_Matsumoto2)\ **Post date:** [30 July 2003 17:33 UTC](https://rubytalk.org/t/warnings/7079/9 "2003-07-30T17:33:31Z")
Hi, > How can this feature be accessed from inside Ruby code? $VERBOSE = nil # to make it silent > Will it be possible to turn up the warning level? My personal > preference would be to always use the highest warning level possible. $VERBOSE = false # to make it normal level $VERBOSE = true # to make it verbose ``` matz. ``` > **···** > > In message “Re: Warnings?” on 03/07/30, Paul Brannan [pbrannan@atdesk.com](mailto:pbrannan@atdesk.com) writes: ---
**Author:** ![Michael\_Davis1](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@Michael\_Davis1](https://rubytalk.org/u/Michael_Davis1)\ **Post date:** [29 July 2003 23:54 UTC](https://rubytalk.org/t/warnings/7079/10 "2003-07-29T23:54:09Z")
I can appreciate the difficulty, however, I would rather not suppress all warnings and yet I have code that generates warnings that are okay. Will it be possible to turn off warnings and then turn them back on again at runtime? This would at least provide me an option to disable warning messages during methods that generate warnings. Thanks, Michael Davis Yukihiro Matsumoto wrote: > **···** > > > Hi, > > > > In message “Re: Warnings?” \> on 03/07/30, Michael Davis [mdavis@sevasoftware.com](mailto:mdavis@sevasoftware.com) writes: > > > > > How about a way to trap warnings similar to rescue Exception so we can trap and suppress certain expected warnings? > > > > Since warning is a mere message, not exit like exceptions, it is more > > difficult to catch. You can suppress warning messages by redirecting > > $stderr temporarily (although it’s not thread safe). > > > > ``` > > matz. > > > > ``` ---
**Author:** ![Robert](https://avatars.discourse-cdn.com/v4/letter/r/e95f7d/32.png) [@Robert](https://rubytalk.org/u/Robert)\ **Post date:** [30 July 2003 02:27 UTC](https://rubytalk.org/t/warnings/7079/11 "2003-07-30T02:27:29Z")
“Yukihiro Matsumoto” [matz@ruby-lang.org](mailto:matz@ruby-lang.org) schrieb im Newsbeitrag news:1059507455.553355.1938.nullmailer@picachu.netlab.jp… > Hi, > > > How about a way to trap warnings similar to rescue Exception so we can > > trap and suppress certain expected warnings? > > Since warning is a mere message, not exit like exceptions, it is more > difficult to catch. You can suppress warning messages by redirecting > $stderr temporarily (although it’s not thread safe). The approach most reasonable is IMHO to provide a warning handler setting mechanism similarly to the trace handler. Only I don’t know how much runtime overhead that’d be. The handler block could receive something like > level, code, message, sender| and treat it appropriately. -W0, -W1 etc. > would then change the block’s filtering according to level. Or should we use a mature logging feature? Maybe [Log4r - Logging system written in Ruby download | SourceForge.net](http://sourceforge.net/projects/log4r/) or a smaller solution. Matz, what do you think? Regards ``` robert ``` > **···** > > > In message “Re: Warnings?” \> on 03/07/30, Michael Davis [mdavis@sevasoftware.com](mailto:mdavis@sevasoftware.com) writes: ---
**Author:** ![Michael\_Davis1](https://avatars.discourse-cdn.com/v4/letter/m/eb8c5e/32.png) [@Michael\_Davis1](https://rubytalk.org/u/Michael_Davis1)\ **Post date:** [30 July 2003 20:49 UTC](https://rubytalk.org/t/warnings/7079/12 "2003-07-30T20:49:06Z")
Thanks, this worked great. Yukihiro Matsumoto wrote: > **···** > > > Hi, > > > > In message “Re: Warnings?” \> on 03/07/30, Paul Brannan [pbrannan@atdesk.com](mailto:pbrannan@atdesk.com) writes: > > > > > How can this feature be accessed from inside Ruby code? > > > > $VERBOSE = nil # to make it silent > > > > > Will it be possible to turn up the warning level? My personal > > > preference would be to always use the highest warning level possible. > > > > $VERBOSE = false # to make it normal level > > $VERBOSE = true # to make it verbose > > > > ``` > > matz. > > > > ``` ---
**Author:** ![Austin\_Ziegler2](https://avatars.discourse-cdn.com/v4/letter/a/ad7895/32.png) [@Austin\_Ziegler2](https://rubytalk.org/u/Austin_Ziegler2)\ **Post date:** [30 July 2003 00:38 UTC](https://rubytalk.org/t/warnings/7079/13 "2003-07-30T00:38:13Z")
This seems to work, at least in irb: irb(main):001:0\> class WarningException \< Exception; end irb(main):002:0\> module Kernel irb(main):003:1\> def warn(m) irb(main):004:2\> raise WarningException, m irb(main):005:2\> end irb(main):006:1\> end irb(main):007:0\> warn “Hello” (irb):4:in `warn': Hello (WarningException) from (irb):7:in `irb\_binding’ from C:/Apps/Ruby18/lib/ruby/1.8/irb/workspace.rb:52:in `irb\_binding’ from C:/Apps/Ruby18/lib/ruby/1.8/irb/workspace.rb:52 This, of course, depends on the module using the functionality. It also won’t work on rb\_warning or rb\_warn, obviously. -austin > **···** > > On Wed, 30 Jul 2003 08:54:09 +0900, Michael Davis wrote: > > > I can appreciate the difficulty, however, I would rather not suppress all > > warnings and yet I have code that generates warnings that are okay. Will > > it be possible to turn off warnings and then turn them back on again at > > runtime? This would at least provide me an option to disable warning > > messages during methods that generate warnings. > > – > austin ziegler \* austin@halostatue.ca \* Toronto, ON, Canada > software designer \* pragmatic programmer \* 2003.07.29 > \* 20.31.14 ---
**Author:** ![Ben\_Giddings](https://avatars.discourse-cdn.com/v4/letter/b/b19c9b/32.png) [@Ben\_Giddings](https://rubytalk.org/u/Ben_Giddings)\ **Post date:** [30 July 2003 00:56 UTC](https://rubytalk.org/t/warnings/7079/14 "2003-07-30T00:56:12Z")
When you say you have “code that generates warnings that are ok”, you mean the warnings are safe to ignore, or code that generates warnings that looks ok to you? And when you say “turn them back on again at runtime”, do you mean a variable you can change programmatically, or a function you can run that determines whether warnings go to the console or not? A typical unix way of dealing with output you don’t care about is redirecting it to /dev/null, so you could create methods that reassign $stderr to the default value or /dev/null depending on whether or not you want to see them: def warningsOn $stderr.flush $stderr = STDERR end def warningsOff $stderr.flush $stderr = File.open(‘/dev/null’, ‘w’) end (thinks _why_ for the prototype) Ben > **···** > > On Tuesday, July 29, 2003, at 07:54 PM, Michael Davis wrote: > > > I can appreciate the difficulty, however, I would rather not suppress > > all warnings and yet I have code that generates warnings that are > > okay. Will it be possible to turn off warnings and then turn them > > back on again at runtime? This would at least provide me an option to > > disable warning messages during methods that generate warnings. ---
**Author:** ![Laurent\_Julliard4](https://avatars.discourse-cdn.com/v4/letter/l/ebca7d/32.png) [@Laurent\_Julliard4](https://rubytalk.org/u/Laurent_Julliard4)\ **Post date:** [30 July 2003 02:28 UTC](https://rubytalk.org/t/warnings/7079/15 "2003-07-30T02:28:01Z")
> The approach most reasonable is IMHO to provide a warning handler setting > mechanism similarly to the trace handler. Only I don’t know how much > runtime overhead that’d be. The handler block could receive something like > > > level, code, message, sender| and treat it appropriately. -W0, -W1 etc. > > would then change the block’s filtering according to level. I proposed a think like this ! I’m not alone ! 🙂 Oh, and a $VERBOSE as $VERBOSE={ ‘version\_warnings’=\>true, ‘uninitialized\_vars’=\>false, ‘redefined\_nethode’=\>true} well, with more elements:) > Or should we use a mature logging feature? Maybe > [Log4r - Logging system written in Ruby download | SourceForge.net](http://sourceforge.net/projects/log4r/) or a smaller solution. Matz, what do > you think? devel/logger could fit? > **···** > > il Tue, 29 Jul 2003 22:53:41 +0200, “Robert Klemme” [bob.news@gmx.net](mailto:bob.news@gmx.net) ha scritto::