Descompose memory result

guif · 12-17-2008, 11:35 AM

I use this command to give my free memory in my system: free | grep Mem | awk '{ print $4 }'

And, I would like to know what's the arithmetical math to descompose this result into Gb, Mb and Kbytes.
For example, If I have 1048577Kbyes

1048577 / 1024 = 1024,0009 Mb
1024,0009 / 1024 = 1 Gb

my result: 1GB, 1Mb, 0Kbytes.

I would like to make this with and script.

Help me please!

jonaskoelker · 12-17-2008, 03:16 PM

To get the quotient and remainder from integer division, try this:

Code:

$ python -c "for x in divmod(8, 3): print x

replace 8 with your awk output and 3 with 1024 and you should have something to work with.

guif · 12-18-2008, 06:59 AM

wow! thanks for your answer. but i don't understand...

I have this:

Code:

#!/bin/bash

MEMTOTAL=`free | grep Mem | awk '{ print $2 }'`
MEMUSED=`free | grep Mem | awk '{ print $3 }'`
MEMFREE=`free | grep Mem | awk '{ print $4 }'`

echo "Total: "`expr $MEMTOTAL / 1048576`"Gb"
echo "Used: "`expr $MEMUSED / 1024`"Mb" "($MEMUSED Kb)"
echo "Free: "`expr $MEMFREE / 1024`"Mb" "($MEMFREE Kb)"

Now, how can i added your code?

guif · 12-29-2008, 12:03 PM

anybody help me?

jcookeman · 12-29-2008, 02:38 PM

Bash doesn't do floating point precision. So, if you want to do this in pure Bash, you will lose precision. However, you can use awk or bc if you don't want to use Python as already proposed. However, it is much less readable:

Code:

#!/usr/bin/env bash

FREE_BYTES=$(free | grep Mem | awk '{ print $4 }')
FMT=(KB MB GB)

RTR=($(bc <<EOF
/* Two points of floating precision */
scale = 2
free = $FREE_BYTES;
index = 0;
while( free >= 1024 ) {
    free /= 1024;
    index += 1;
}
/* Print converted byte value and index to stdout */
free; index;
EOF
))

echo "Memory free: ${RTR[0]} ${FMT[${RTR[1]}]}"

guif · 01-14-2009, 11:15 AM

very thanks jcookeman.
I study this code. Thanks!

H_TeXMeX_H · 01-14-2009, 11:29 AM

How about the simplest solution of all:

Code:

free -m
free -k
free -b

guif · 01-14-2009, 11:34 AM

I see this code now.
I see that I lose precision. Is more easy in Python??

jcookeman · 01-14-2009, 11:55 AM

Quote:

Originally Posted by guif

I see this code now.
I see that I lose precision. Is more easy in Python??

The code that I posted does not lose precision.

guif · 01-15-2009, 05:44 AM

oh sorry! I check it wrong with my calc.