Process substitution into loop

[James Hunt]

Hi Grail,

On 10/06/11 05:46, Grail Dane wrote:
> 
> 
>> Date: Thu, 9 Jun 2011 21:05:45 -0700
>> From: steve.langasek at ubuntu.com
>> To: grail69 at hotmail.com
>> CC: upstart-devel at lists.ubuntu.com
>> Subject: Re: Process substitution into loop
>>
>> On Fri, Jun 10, 2011 at 03:53:15AM +0000, Grail Dane wrote:
>> > Just wondering, as I can't find by googling, if it is at all possible to
>> > do a processsubstitution into a while loop within an upstart script?
>>
>> > Example:
>> > while read -r DEVICE
>> > do
>> > ip link set dev $DEVICE up
>> > done< <(ip link | awk '/^[0-9]/ && !/UP/ && gsub(/:/,""){print $2})
You have an error in your script: it is missing the closing tick (see below).

>>
>> > When issuing the start command on the script I get:
>> > /proc/self/fd/10: line 6: syntax error near unexpected '<'init:
>> > network-interfaces main process (1367) terminated with status 2start: Job
>> > failed to start Would appreciated if someone would identify if i have done
>> > something wrong or if this not a supported feature?
>>
>> The <() syntax is not part of the POSIX standard, it's a bash extension.
>> Upstart uses /bin/sh to interpret scripts, as is customary; chances are
>> you're running on a system where /bin/sh is not bash, and as a result this
> 
> Actually /bin/sh is a symbolic link to bash on my system.  Is there anyway to have bash as the
> shell used?

script
/bin/bash <<EOT
while read -r DEVICE
do
    echo "DEBUG: ip link set dev $DEVICE up" > /tmp/grail.log
done < <(ip link | awk '/^[0-9]/ && !/UP/ && gsub(/:/,""){print $2}')
EOT
end script

Also, just for you :)...

http://upstart.ubuntu.com/cookbook/#changing-the-default-shell

Regards,

James.

> 
>> syntax is not supported.
>>
>> A supported syntax would be:
>>
>> ip link | awk '/^[0-9]/ && !/UP/ && gsub(/:/,""){print $2}' |
>> while read -r DEVICE
>> do
>> ip link set dev $DEVICE up
>> done
>>
>> --
>> Steve Langasek Give me a lever long enough and a Free OS
>> Debian Developer to set it on, and I can move the world.
>> Ubuntu Developer http://www.debian.org/
>> slangasek at ubuntu.com vorlon at debian.org
>