Re^3: sumof - attempting to sum a column from each file

[CountZero]

Try this for your summing code:

use Modern::Perl;

my $sum_of_used;
{
    no warnings qw/numeric uninitialized/;
    $sum_of_used += (split /\s+/)[2] while <DATA>;
}
say $sum_of_used;

__DATA__
<df -k>
Filesystem               total       used      avail capacity  Mounted
+ on
/vol/vol0/          142606336KB  5274244KB 137332092KB      4%  /vol/v
+ol0/
/vol/vol0/.snapshot 35651584KB   923524KB 34728060KB       3%  /vol/vo
+l0/.snapshot
/vol/vobstore/      734003200KB  6335232KB 727667968KB       1%  /vol/
+vobstore/
/vol/vobstore/.snapshot 183500800KB   260200KB 183240600KB       0%  /
+vol/vobstore/.snapshot
/vol/ccase/         125829120KB 21814420KB 104014700KB      17%  /vol/
+ccase/
/vol/ccase/.snapshot 31457280KB    90572KB 31366708KB       0%  /vol/c
+case/.snapshot
/vol/viewstore/     943718400KB  6492604KB 937225796KB       1%  /vol/
+viewstore/
/vol/viewstore/.snapshot 235929600KB   137500KB 235792100KB       0%  
+/vol/viewstore/.snapshot
/vol/viewstore_win/ 67108864KB      480KB 67108384KB       0%  /vol/vi
+ewstore_win/
/vol/viewstore_win/.snapshot 16777216KB     2372KB 16774844KB       0%
+  /vol/viewstore_win/.snapshot
</df -k>

It can be so simple because Perl knows how to make a number out of "almost" numbers. In other words, Perl simply disregards the 'KB' which is attached to the number. Everything which does not contain numbers will become 0, such as the header line. A perfect example of Perlish "Do What I Mean".

Of course I had to switch of the "not numeric" and "not initialized" warnings, but that is OK if you know what you are doing.