[SOLVED] Calculating Values of Fields

Hi_This_is_Dev · 09-01-2009, 08:28 AM

Hi,

Kindly have a look at this output:

Code:

[root@localhost ~]# free
             total       used       free     shared    buffers     cached
Mem:        506940     423120      83820          0      26744     120692
-/+ buffers/cache:     275684     231256
Swap:      1052248          0    1052248
[root@localhost ~]# free | tee diskInfo | grep Swap | cut -d: -f2
      1052248          0    1052248
[root@localhost ~]#

Now, what I want to do is calculate a percentage value of Swap utilization so as to show how much space is free or utilized- in percentage.

I want to capture/store all the three values (in variables), as shown above in the result of the second command, separately so that I can further use those variables to perform the calculation.

Some correction is needed to be done in the "cut" fragment of the second command.

Can you show it?

David the H. · 09-01-2009, 09:28 AM

If all you want is just the numbers and a percentage output, awk would be a better choice. It can even do the calculations for you.

Code:

david:[~]$ free | awk '/Swap/ {print "total:",$2,"\nused:",$3,"\nfree:",$4,"\n% used:",($3/$2*100),"\n% free:",($4/$2*100)}'
total: 1461872
used: 5108
free: 1456764
% used: 0.349415
% free: 99.6506

If you really need them in variables for other purposes, then it's easy to add the values to an array in the same fashion:

Code:

david:[~]$ freearray=( $(free|awk '/Swap/ {print $2,$3,$4}') )

david:[~]$ echo "${freearray[0]}
1461872
david:[~]$ echo "${freearray[1]}
5108
david:[~]$ echo "${freearray[2]}
1456764

kdelover · 09-01-2009, 09:35 AM

just a small addition id prefer adding free -om

Hi_This_is_Dev · 09-01-2009, 10:16 AM

I have tried the following and it is great! I will try the first one also, but tomorrow.

It's time to go and take rest!

Quote:

Originally Posted by David the H.

If you really need them in variables for other purposes, then it's easy to add the values to an array in the same fashion:

Code:

freearray=( $(free|awk '/Swap/ {print $2,$3,$4}') )

echo "${freearray[0]}"

echo "${freearray[1]}"

echo "${freearray[2]}"