How to display result of df every 30s?

Question

All I want to see is the % after I issue df / every 30s but on the same line just after the previous number.

So the final output would be 86% 86% 86% 87% 87% ......

Could it be one line code? Or multiple line 'program'?

score 24 · Answer 1 · answered Apr 23 '13 at 05:41

24

I'd prefer

watch -n 30 df

Man watch:

watch - execute a program periodically, showing output fullscreen

answered Apr 23 '13 at 05:41

superuser0

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What is the advantage over my watch solution that at least only displays the root filesystem? – Anthon Apr 23 '13 at 05:51
3

Upvoted because I didn't know that watch existed. But I don't think your solution can deliver what I asked for. – Radek Apr 23 '13 at 05:53
@Radek I just asked because it seemed a copy of my answer coming in 9 minutes later as well showing even more that you did not want. – Anthon Apr 23 '13 at 06:19
Your answer wasn't there when I started to write mine, I also edited my post a bit later and maybe it displays that time as the posting time. I certainly don't copy answers. – superuser0 Apr 23 '13 at 06:39

score 6 · Accepted Answer · answered Apr 23 '13 at 05:40

6

while printf '%s ' "$(df -P / | awk 'NR==2 { print $(NF-1) }')"; do
    sleep 30
done
echo

answered Apr 23 '13 at 05:40

Chris Down

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one-liner `while printf '%s ' "$(df -P / | awk 'NR==2 { print $(NF-1) }')"; do sleep 30; done` thank you – Radek Apr 23 '13 at 06:08
What would be syntax for alias? I cannot make it work... alias df2='while printf \'%s \' "$(df -P / | awk \'NR==2 { print $(NF-1) }\')"; do sleep 30; done' is not correct – Radek Apr 23 '13 at 06:12

score 4 · Answer 3 · answered Apr 23 '13 at 05:33

4

you can use watch:

watch -n 30 -t df /

But that overwrites the existing output

answered Apr 23 '13 at 05:33

Anthon

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You should read again what he wants. – Hauke Laging Apr 23 '13 at 05:35

score 2 · Answer 4 · answered Apr 23 '13 at 05:38

2

Crude, but works:

while true; do printf "%s " $(df / | awk '/root/ {print $5}'); sleep 30; done

answered Apr 23 '13 at 05:38

jasonwryan

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Shouldn't be the text = inside to loop? – Radek Apr 23 '13 at 05:40
1

But this would be every 30s + execution time of df, right? – Bernhard Apr 23 '13 at 05:42
1

Made it a one-liner... – jasonwryan Apr 23 '13 at 05:43
one-liner that can be run from a command line not from the script? If I copy&paste your code into command line and press enter it does nothing. – Radek Apr 23 '13 at 05:46
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@Radek The `root` may be the problem. Adapt to your putput of `df /` or take my `NR==2`. – Hauke Laging Apr 23 '13 at 05:48
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@Bernhard I think if someone cannot live with such an inaccuracy of about 1:3000 (on my system) then I would expect him to mention that in his question. – Hauke Laging Apr 23 '13 at 05:52
@HaukeLaging: Thank you that helped. Now I have working one-liner! :-) – Radek Apr 23 '13 at 05:57
@Hauke Of course, I just wanted to be precise :) – Bernhard Apr 23 '13 at 06:17
Optional uglification: `while( sleep 30 ) do ...`. Saves 5 chars at the cost of readability. – Hennes Apr 23 '13 at 14:29
@Hennes Thanks: any uglification is good for me... :) – jasonwryan Apr 23 '13 at 19:41

score 1 · Answer 5 · answered Apr 23 '13 at 05:43

1

For bash:

i=1
outputs_per_line=10
frequency=30
while true; do
  echo -n "$(df / | awk 'NR==2 {print $5}') "
  if [ $((i%outputs_per_line)) -eq 0 ]; then
    echo
  fi
  ((i++))
  sleep "$frequency"
done

The line break after $outputs_per_line numbers shall prevent a console line break within the output.

answered Apr 23 '13 at 05:43

Hauke Laging

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@Anthon If I had just made it `sleep 30` I might have been fast enough... – Hauke Laging Apr 23 '13 at 05:45
Interesting how your edit doesn't show up as a revision. I will delete my comment, now it seems inappropriate – Anthon Apr 23 '13 at 05:47
@Anthon I assume there's a threshold of a few seconds or minutes below which revisioning is considered not useful. – Hauke Laging Apr 23 '13 at 05:49
That is probably it. I am not sure if your change was there before I commented. I would expect you were first, and that a comment would reduce the grace period for editing (to prevent these kind of discussions). I will browse meta (SO) to see if there is something. – Anthon Apr 23 '13 at 05:54

How to display result of df every 30s?

5 Answers5