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Re: lost output from asynchronous lists


From: Eric Blake
Subject: Re: lost output from asynchronous lists
Date: Wed, 29 Oct 2008 06:26:56 -0600
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According to Eric Blake on 10/29/2008 6:22 AM:
>>> -  ( :; $1 ) >"$at_stdout" 2>"$at_stderr"
>>> +  : >"$at_stderr"
>>> +  ( :; $1 ) >>"$at_stdout" 2>>"$at_stderr"
>> What's the ":;" for?
> 
> A workaround to the bash 3.2 bug, fixed in bash32-030, where failure to
> use :; prior to a compound command (except for a subshell) meant that bash
> incorrectly returns status 0 if redirection fails.

Sorry; I thought it was a different use of :;.  In this case, it is a
workaround to the case where the m4 argument $1 is empty or only
whitespace, and is necessary so that the shell code formed is valid (a
subshell must contain a command list).

- --
Don't work too hard, make some time for fun as well!

Eric Blake             address@hidden
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