如何选择要显示警告的文件？

Question

要使用Ruby显示警告,可以ruby使用标志调用-w.使用库时,Ruby可能会显示许多警告,因此很难从您实际处理的文件中找到警告.是否可以告诉ruby仅显示某些文件的警告？

这是一个说明问题的例子.下面加载一个生成大量警告的库,它还通过重新定义常量自行生成警告.

require 'grooveshark'

CONSTANT = 'foo'
CONSTANT = 'bar'

输出ruby -w warning_test.rb如下:

/var/lib/gems/1.9.1/gems/rest-client-1.6.7/lib/restclient/exceptions.rb:157: warning: assigned but unused variable - message
/var/lib/gems/1.9.1/gems/rest-client-1.6.7/lib/restclient/exceptions.rb:167: warning: assigned but unused variable - message
/var/lib/gems/1.9.1/gems/rest-client-1.6.7/lib/restclient/response.rb:11: warning: method redefined; discarding old body
/var/lib/gems/1.9.1/gems/rest-client-1.6.7/lib/restclient/payload.rb:47: warning: mismatched indentations at 'end' with 'case' at 40
/var/lib/gems/1.9.1/gems/macaddr-1.6.1/lib/macaddr.rb:63: warning: assigned but unused variable - status
/var/lib/gems/1.9.1/gems/macaddr-1.6.1/lib/macaddr.rb:63: warning: assigned but unused variable - stderr
/var/lib/gems/1.9.1/gems/macaddr-1.6.1/lib/macaddr.rb:56: warning: assigned but unused variable - re
/var/lib/gems/1.9.1/gems/macaddr-1.6.1/lib/macaddr.rb:59: warning: assigned but unused variable - null
/var/lib/gems/1.9.1/gems/systemu-2.5.2/lib/systemu.rb:126: warning: shadowing outer local variable - cid
/var/lib/gems/1.9.1/gems/systemu-2.5.2/lib/systemu.rb:213: warning: shadowing outer local variable - buf
/var/lib/gems/1.9.1/gems/systemu-2.5.2/lib/systemu.rb:215: warning: shadowing outer local variable - buf
/var/lib/gems/1.9.1/gems/systemu-2.5.2/lib/systemu.rb:208: warning: assigned but unused variable - ignored
/var/lib/gems/1.9.1/gems/systemu-2.5.2/lib/systemu.rb:252: warning: shadowing outer local variable - key
/var/lib/gems/1.9.1/gems/systemu-2.5.2/lib/systemu.rb:249: warning: assigned but unused variable - ignored
/var/lib/gems/1.9.1/gems/grooveshark-0.2.7/lib/grooveshark/user.rb:65: warning: method redefined; discarding old playlists
/var/lib/gems/1.9.1/gems/grooveshark-0.2.7/lib/grooveshark/user.rb:93: warning: method redefined; discarding old favorites
warning_test.rb:4: warning: already initialized constant CONSTANT

在这种情况下,我只想看到最后一个警告

warning_test.rb:4: warning: already initialized constant CONSTANT

由于其他警告是由于库,我没有直接控制它们的警告不是那么有趣.我希望能够告诉Ruby只显示正在运行的项目的警告.

我意识到定义电流可能很棘手.也许只显示给定文件的警告和通过包含的文件require_relative.另一种方法是显示与给定文件的目录结构相近的文件的警告.

Answer 1

您可以将 stderr 重定向到 stdout，然后再重定向到 grep。这是一个例子：

ruby -w warning_test.rb 2>&1 | grep "warning_test"