RHEL Release 5.5 (Tikanga), df --total option

Question

I have a RHEL (Redhat Enterprise Linux) v6.5 (Santiago) server. On this server if i do a df -help there are list of options available. I am interested in the option --total However there is an older version of RHEL (v5.5). In which there is no --total option.

My question is, I have a command like this:

df -h --total  | grep total | awk 'NR==1{print$2}+NR==1{print$3}+NR==1{print$4}+NR==1{print$5}'

which gives the output as

62G
39G
21G
66%

Where

62G is Total size of the Disk
39G is Used
21G is remaining
61% Total usage %

The above command is working fine in RHEL v6.5. But fails in RHEL v5.5 since it does not have a --total option for df command.

When i run the same command on RHEL v5.5 i get the below error:

df: unrecognized option `--total'
Try `df --help' for more information.

So is there a command that can give me the output in the following way:

Total Disk Space
Used  Space
Remaining Disk space
Usage % 

Ex:

62G
39G
21G
66%

Answer 1

You'll have to do the calculation work yourself.

Something like this awk script should work.

$ cat dftotal.awk
BEGIN {
    map[0] = "K"
    map[1] = "M"
    map[2] = "G"
    map[3] = "T"
}
function fmt(val,    c) {
    c=0
    while (val > 1024) {
        c++
        val = val / 1024
    }
    return val map[c]
}

{
    for (i=2;i<5;i++) {
        sum[i]+=$i
    }
}

END {
    print fmt(sum[2]) ORS fmt(sum[3]) ORS fmt(sum[4])
    print ((sum[3] / sum[2]) * 100) "%"
}
$ df -P | awk -f dftotal.awk