Append to a file repeating output


 
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# 1  
Old 09-08-2015
Append to a file repeating output

Hello,

i'm trying to force a command to read every second from an interface

Code:
watch  -n1 (command) /dev/x | cat  >> output

but it continue to overwrite the file, without append the content

Thanks and advace for help as usual

regards
# 2  
Old 09-08-2015
What does commanddo to the output file? You know that that cat is unnecessary?
# 3  
Old 09-08-2015
hello,

just write 4 columns of raw data, like a timestamp and numbers. Yes i've tried also without it and without the pipe using just >> , again still the same.

Thank you
# 4  
Old 09-08-2015
So - why did you put it back in?

watch seems to do funny things to your output file, e.g. writing many console code/control chars. You should have seen it grow during operation.
# 5  
Old 09-08-2015
Place the whole command to watch within single coma.
Code:
watch  -n1 'command /dev/x | cat  >> output'

However, the command cat it not necessary there.

Code:
watch  -n1 'command /dev/x >> output'

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