Re: [Findutils-patches] xargs problem

[aws backup]

Thank you Berny. 
You helped me a lot :-)
Wish you the best.
Robert


> On 21 Dec 2016, at 08:40, Bernhard Voelker <address@hidden> wrote:
> 
> On 12/20/2016 10:35 PM, aws backup wrote:
>> Ok I started the screen command like this:
>> 
>> *screen -dmS test /bin/bash -c "/path/to/fswatch.sh"*
> 
> if the script is executable, then you can omit the "/bin/bash -c" here.
> 
>> then the first script fswatch.sh:
>> 
>> *#!/bin/bash
>> fswatch -0 -Ie '.*\.*$' -i '.*\.mp4$' /path/to/folder \
>>     | xargs -0 -n 1 /path/to/s3cmd.sh*
>> 
>> then the second script s3cmd.sh:
>> 
>> *#!/bin/bash
>> filename="$(basename "$1")"
>> terminal-notifier -message "s3cmd Upload '$filename' started"
>> 
>> s3cmd put "$1" s3://bucket/ \
>>   | tee /path/to/logfile.txt \
>>   | tee >(mail -s 'Upload $filename' address@hidden <mailto:address@hidden>) 
>> \
>>       && /usr/local/bin/terminal-notifier -message "s3cmd Upload of 
>> '$filename' done"*
>> *
>> *
>> The second tee command is to get the output also in the screen terminal to 
>> see what's going on when I attach the screen.
> 
> tee can do that, maybe you look here to find out how:
>  http://www.gnu.org/software/coreutils/tee
> 
>> Now what's happening. I change a filename. xargs transfers first the old 
>> file name (before renaming) to the script.
>> Therefore I get the notifications upload started and upload done for the old 
>> filename and following error from s3cmd
>> (also as email): 
>> 
>> *ERROR: Parameter problem: Nothing to upload.*
>> *Null message body; hope that's ok*
>> *
>> *
>> Which is correct because the old file is not existing anymore. 
>> 
>> Then xargs transfers the new file name (after renaming) to the script and 
>> everything works as expected. Just the
>> variable "$filename" in the mail command doesn't work. The subject of the 
>> notification email is "Upload $filename".
>> 
>> How can I avoid that the old file name is transferred to the script?
> 
> I do not know fswatch, so you should have a look into its manual how
> to suppress that.
> 
>> Why does the mail command not understand $filename?
> 
> This is because you have single quotes ('...') around the message text.
> Therefore, the shell doe no variable expansion.
> 
>  $ v=world
>  $ echo 'hello $v'
>  hello $v
>  $ echo "hello $v"
>  hello world
> 
> But all this is far beyond the initial xargs question.  You're probably
> much better off asking in some shell scripting forum than here on the
> findutils project mailing list.
> 
> Have a nice day,
> Berny