Question

I often work on unix boxes that don’t have the -h flag for du.

I am looking for a one-liner to convert KB to human readable. Perl seemed like a good choice.

This is what I have so far.

@a=split /\s+/;
$x=$_!=0?int(log()/log(1024)):0;
@b=('K','M','G');
printf("%.3s%s\t%s\n",$_/(1024)**$x,$b[$x],$a[1]);

Run like this:

du -ks * | perl -lne '@a=split /\s+/;$x=$_!=0?int(log()/log(1024)):0;@b=('K','M','G');printf("%.3s%s\t%s\n",$_/(1024)**$x,$b[$x],$a[1]);'

It doesn’t work perfectly as I haven’t been able to find the correct printf format.

one-liners using perl as well as awk/sed, etc. would be the most useful.

This is what du -h looks like. Max 1 decimal. Min: 0 decimals. With Rounding.

8.0K
1.7M
4.0M
5.7M
88K

Update:

du -ks * | perl -lane '$F[0];$x=$_!=?int(log()/log(1024)):0;printf("%.3s%s\t%s\n",$_/1024**$x,qw<K M G>[$x],$F[1]);'

Answer 1

If the only modification you want to make (It’s not clear what you want) is to have the number be right-aligned in a field of 3 characters, simply drop the period from the printf format. Also, rather than explicitly calling split and treating the whole of $_ as a number, I would recommend passing Perl the -a switch, which automatically splits $_ on whitespace into the array @F, and then replace the references to $_ in your code with $F[0].

Your code could thus be rewritten (using a couple more Perlisms and adding some spaces for readability) as:

du -ks * | perl -lane '$x = $F[0] != 0 && int(log($F[0])/log(1024)); printf("%3d%s\t%s\n", $F[0]/1024**$x, qw<K M G>[$x], $F[1]);'