From: Robert Gleeson <rob@...>
Date: 2009-12-12T01:08:16+09:00
Subject: Re: Redirecting standard output


> I probably wasn't specific enough: sub processes which use exec to
> overlay the image will not inherit redirection if you simply assign to
> $stdout:
> 
> 16:24:59 ~$ ruby19 -e '$stdout = File.open("log","w"); puts 123; 
> system("date")'
> Fri Dec 11 16:25:05 WEST 2009
> 16:25:05 ~$ cat -n log
>      1  123
> 16:25:08 ~$ ruby19 -e '$stdout.reopen("log"); puts 456; system("date")'
> 16:25:14 ~$ cat -n log
>      1  456
>      2  Fri Dec 11 16:25:13 WEST 2009
> 16:25:15 ~$

Ah! Okay. It makes sense now :-) Cool, I didn't know that.

>> persist.
> And exactly that is a problem: redirection does not take place for
> whoever owns foo => it failed.

"whoever owns foo => it failed?" ..? I don't see any difference between 
assigning $stdout and using $stdout.reopen in this case.

foo = $stdout = File.open 'foo', 'w'
foo = $stdout.reopen 'foo', 'w'

They're both references to the same object. Can you elaborate or provide 
an example? Thanks.

- Rob


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