Programatically write in a file in the environnent with a hush command

Programatically write in a file in the environnent with a hush command

[Jean-Christophe BEGUE]

Hello,

I'm trying to pass a value from Barebox to the operating system, using
the usreland command bareboxenv -l.

My problem is : How should I write that status from my hush barebox script?

echo $mystatus > /env/data/my_status_file

The above command doesn't work as '>' is not implemented.

I've the feeling that I'm missing something?

Jean-Christophe BEGUE

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Re: Programatically write in a file in the environnent with a hush command

[Alexander Richter]

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Hello,
> Am 26.05.2015 um 17:42 schrieb Jean-Christophe BEGUE <begue.jc@gmail.com>:
> 
> Hello,
> 
> I'm trying to pass a value from Barebox to the operating system, using
> the usreland command bareboxenv -l.
> 
> My problem is : How should I write that status from my hush barebox script?
> 
> echo $mystatus > /env/data/my_status_file
You can use the command nv to create non volatile shell variables. Don’t forget to save the Environment.
> 
> The above command doesn't work as '>' is not implemented.
> 
> I've the feeling that I'm missing something?
> 
To access the new variable (/env/nv/foo.bar) from userspace, you can use the „bareboxenv“ tool

Alexander Richter

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Re: Programatically write in a file in the environnent with a hush command

[Alexander Richter]

> Am 27.05.2015 um 08:10 schrieb Alexander Richter <alexander.richter@atsonline.de>:
> 
> Hello,
>> Am 26.05.2015 um 17:42 schrieb Jean-Christophe BEGUE <begue.jc@gmail.com>:
>> 
>> Hello,
>> 
>> I'm trying to pass a value from Barebox to the operating system, using
>> the usreland command bareboxenv -l.
>> 
>> My problem is : How should I write that status from my hush barebox script?
>> 
>> echo $mystatus > /env/data/my_status_file
> You can use the command nv to create non volatile shell variables. Don’t forget to save the Environment.
Additionally, a echo -a / -o might be useful in your case.
-a <file>",  "instead of outputting to stdout append to <file>
-o <file>",  "instead of outputting to stdout overwrite <file>
>> 
>> The above command doesn't work as '>' is not implemented.
>> 
>> I've the feeling that I'm missing something?
>> 
> To access the new variable (/env/nv/foo.bar) from userspace, you can use the „bareboxenv“ tool
> 
> Alexander Richter
> _______________________________________________
> barebox mailing list
> barebox@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/barebox

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Re: Programatically write in a file in the environnent with a hush command

[Sascha Hauer]

Hi Jean-Christophe,

On Tue, May 26, 2015 at 05:41:06PM +0200, Jean-Christophe BEGUE wrote:
> Hello,
> 
> I'm trying to pass a value from Barebox to the operating system, using
> the usreland command bareboxenv -l.
> 
> My problem is : How should I write that status from my hush barebox script?
> 
> echo $mystatus > /env/data/my_status_file
> 
> The above command doesn't work as '>' is not implemented.
> 
> I've the feeling that I'm missing something?

Besides the ways Alexander just mentioned you could also add something
to the kernel cmdline and parse /proc/cmdline later in userspace.
Still another possibility is to add nodes/properties to the device tree
using the of_* commands.

Sascha


-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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Re: Programatically write in a file in the environnent with a hush command

[Jean-Christophe BEGUE]

I didn't noticed -a and -o options for echo. That suits my needs, but
"nv" is exactly what I'm trying to acheive.

I'll use the kernel command line as well on early phases of my software boot.

Thank you!

Jean-Christophe BEGUE
http://www.devisubox.com


On Wed, May 27, 2015 at 8:53 AM, Sascha Hauer <s.hauer@pengutronix.de> wrote:
> Hi Jean-Christophe,
>
> On Tue, May 26, 2015 at 05:41:06PM +0200, Jean-Christophe BEGUE wrote:
>> Hello,
>>
>> I'm trying to pass a value from Barebox to the operating system, using
>> the usreland command bareboxenv -l.
>>
>> My problem is : How should I write that status from my hush barebox script?
>>
>> echo $mystatus > /env/data/my_status_file
>>
>> The above command doesn't work as '>' is not implemented.
>>
>> I've the feeling that I'm missing something?
>
> Besides the ways Alexander just mentioned you could also add something
> to the kernel cmdline and parse /proc/cmdline later in userspace.
> Still another possibility is to add nodes/properties to the device tree
> using the of_* commands.
>
> Sascha
>
>
> --
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |

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