Check file exists on the appvm from dom0 viw qvm-run or other variants?

[Eva Star]

How to check that file exists on AppVm from dom0 bash script? 

Or simple get the exit code of the remote process? 

status=$(qvm-run --pass-io $appvm "test -r $file; echo $?" > file_with_exit_code_always_with_null_why

status=$(qvm-run --pass-io $appvm "cat $file" > dom0file

If $file is not exists how to get notify about it on bash script?

thanks

[Ivan]

On 07/05/2016 12:04 AM, Eva Star wrote:
> How to check that file exists on AppVm from dom0 bash script?
>
> Or simple get the exit code of the remote process?
>
> status=$(qvm-run --pass-io $appvm "test -r $file; echo $?" >
> file_with_exit_code_always_with_null_why

no need to echo $?, the exit code is passed to dom0 too. Eg.:

# qvm-run --pass-io $appvm "test -e /bin/ls"
# echo $?
0

# qvm-run --pass-io $appvm "test -e /bin/blah"
# echo $?
1

>
> status=$(qvm-run --pass-io $appvm "cat $file" > dom0file
> If $file is not exists how to get notify about it on bash script?

if ! $(qvm-run --pass-io $appvm "test -e $file"); then
your_commands_here; fi

but you'll also catch qvm-run errors (eg. $appvm not running). A
workaround would be to choose a custom exit value, like so:

qvm-run --pass-io $appvm "test -e $file || exit 199"
if [ $? -eq 199 ]; then
your_commands_here
fi




> thanks
>

[Eva Star]

Unfortunately, this does not work at bash script, only when you execute echo $? on console its give you right results. When you execute this command with sh script then it always return 0. I think the problem that on bash script its return qvm-run echo code instead of remote code.

[Marek Marczykowski-Górecki]

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Yes, when you include 'echo' (or anything else after that 'test') inside
qvm-run argument, it will shadow exit code. If executing just 'test -r
somefile' through qvm-run should just work.


- --
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
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