title: Retrieve CPU usage percentage
body: <p>I want to retrieve percentage processor usage but no other commands that show tons of numbers. There's a solution using 'grep' or 'awk' or something like that.</p>
  
  <pre><code>~$ vmstat
  procs -----------memory---------- ---swap-- -----io---- -system-- ----cpu----
   r  b   swpd   free   buff  cache   si   so    bi    bo   in   cs us sy id wa
   0  0 1447984 190232 146508 4983236  0    0     0    10    0    0  2  1 97  0
  </code></pre>
  
  <p>I used the vmstat command, and I only want the 'sy' number in the cpu colon.</p>
  
  <pre><code>top command output :
      [m20176 libvirt-  20   0 4368m 4,0g 3028 S  12,0 25,3  24695:44 kvm               (B[m[39;49m
  
  (B[m25320 libvirt-  20   0 3520m 3,0g 3056 S   2,7 19,2  21786:15 kvm               (B[m[39;49m
  
  (B[m    1 root      20   0 10656  624  596 S   0,0  0,0   5:46.26 init              (B[m[39;49m
  (B[m    2 root      20   0     0    0    0 S   0,0  0,0   0:00.12 kthreadd          (B[m[39;49m
  (B[m    3 root      20   0     0    0    0 S   0,0  0,0 476:10.20 ksoftirqd/0       (B[m[39;49m
  (B[m    6 root      rt   0     0    0    0 S   0,0  0,0   0:08.16 migration/0       (B[m[39;49m
  (B[m    7 root      rt   0     0    0    0 S   0,0  0,0   2:03.06 watchdog/0        (B[m[39;49m
  (B[m    8 root      rt   0     0    0    0 S   0,0  0,0   0:04.30 migration/1       (B[m[39;49m
  (B[m   10 root      20   0     0    0    0 S   0,0  0,0   0:38.83 ksoftirqd/1       (B[m[39;49m
  (B[m   12 root      rt   0     0    0    0 S   0,0  0,0   1:43.93 watchdog/1        (B[m[39;49m
  (B[m   13 root      rt   0     0    0    0 S   0,0  0,0   0:03.41 migration/2       (B[m[39;49m
  (B[m   15 root      20   0     0    0    0 S   0,0  0,0   2:42.22 ksoftirqd/2       (B[m[39;49m
  (B[m   16 root      rt   0     0    0    0 S   0,0  0,0   1:49.23 watchdog/2        (B[m[39;49m
  (B[m   17 root      rt   0     0    0    0 S   0,0  0,0   0:04.42 migration/3       (B[m[39;49m
  (B[m   19 root      20   0     0    0    0 S   0,0  0,0 408:06.08 ksoftirqd/3       (B[m[39;49m
  </code></pre>
  
  <p>Here, process uses per process are displayed (only a part). I found this command :</p>
  
  <pre><code>`top -b -d1 -n1|grep -i "Cpu(s)"|head -c21|cut -d ' ' -f3|cut -d '%' -f1`
  </code></pre>
  
  <p><a href="https://askubuntu.com/questions/68741/finding-cpu-usage-from-top-command">here</a>. But this is CPU usage from startup, not real-time usage.</p>