print output of iostat -xnmpztc 2

[mazeem]

iostat -xnmpztc 2
Output

tty cpu
tin tout us sy wt id
1 131 9 1 0 90
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
93.4 34.4 3479.2 576.0 0.0 1.1 0.1 9.0 1 18 c0t0d0
0.1 2.7 5.5 21.3 0.0 0.0 0.1 3.5 0 0 c0t0d0s0 (/)
0.0 0.0 0.0 0.0 0.0 0.0 0.0 4.7 0 0 c0t0d0s1
0.1 0.1 0.8 0.3 0.0 0.0 0.1 17.7 0 0 c0t0d0s3 (/usr)
0.1 0.0 0.6 0.1 0.0 0.0 0.2 4.9 0 0 c0t0d0s4 (/opt)
0.1 19.5 1.9 84.1 0.0 0.0 0.1 2.4 0 3 c0t0d0s5 (/var)
93.0 12.1 3470.4 470.3 0.0 1.1 0.1 10.3 0 17 c0t0d0s7 (/export)

tty cpu
tin tout us sy wt id
22 29104 17 2 0 81
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
10.5 0.0 5459.9 0.0 0.0 0.1 0.1 6.6 0 5 c0t0d0
10.5 0.0 5460.0 0.0 0.0 0.1 0.1 6.6 0 5 c0t0d0s7 (/export)

tty cpu
tin tout us sy wt id
21 32871 11 4 0 85
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
6.5 4.0 1102.6 36.0 0.0 0.1 0.0 7.3 0 6 c0t0d0
0.5 3.0 4.0 24.0 0.0 0.0 0.0 4.1 0 1 c0t0d0s0 (/)
0.0 0.5 0.0 4.0 0.0 0.0 0.0 0.4 0 0 c0t0d0s5 (/var)
6.0 0.5 1098.6 8.0 0.0 0.1 0.0 9.6 0 5 c0t0d0s7 (/export)


tty cpu
tin tout us sy wt id
30 46695 14 5 0 81
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
15.0 86.1 3873.6 377.9 0.0 0.3 0.0 3.3 0 26 c0t0d0
0.0 3.0 0.0 24.0 0.0 0.0 0.0 1.4 0 0 c0t0d0s0 (/)
5.5 83.1 5.5 353.9 0.0 0.2 0.0 1.8 0 16 c0t0d0s5 (/var)
9.5 0.0 3868.0 0.0 0.0 0.2 0.0 18.2 0 16 c0t0d0s7 (/export)

tty cpu
tin tout us sy wt id
16 11026 10 4 0 86
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
220.7 191.1 2988.2 792.6 0.0 1.6 0.0 3.8 1 69 c0t0d0
0.0 191.1 0.0 792.6 0.0 0.3 0.0 1.5 0 28 c0t0d0s5 (/var)
220.7 0.0 2988.2 0.0 0.0 1.3 0.0 5.9 1 65 c0t0d0s7 (/export)


I need the save the 4th iteration of the ouput (not all output)of iostat -xnmpztc 2 to a file
iostat -xnmpztc 2 >> iostat.log
the above command will apend the whole output to iostat.log but i need to save just the 4th iteration to file

tty cpu
tin tout us sy wt id
30 46695 14 5 0 81
extended device statistics
r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device
15.0 86.1 3873.6 377.9 0.0 0.3 0.0 3.3 0 26 c0t0d0
0.0 3.0 0.0 24.0 0.0 0.0 0.0 1.4 0 0 c0t0d0s0 (/)
5.5 83.1 5.5 353.9 0.0 0.2 0.0 1.8 0 16 c0t0d0s5 (/var)
9.5 0.0 3868.0 0.0 0.0 0.2 0.0 18.2 0 16 c0t0d0s7 (/export)

[waynemot]

Since nobody replied to your post let me take a crack at it.

I've had the need to capture the nth pattern from a file and I've found awk/nawk/gawk to be my friend for this. If you make an awk script file that does something like this:

BEGIN {counter = -1; flag = 0; num=num_test;}
{
 if (/^tty cpu/)
  {
   if (flag) exit;
   counter++;
   if (counter == num) flag = 1;
  }
 if (flag) print $0;
}
END {}

then use it like this:

iostat -xnmpztc 2 | awk -f awk-script.awk  -v num-test=4

it should end up with only the 4th block from that output.

Bests,

Way