df -k|perl -ape'map{while(1024<$_){$_/=1024;$i++}$i="%6.1f".substr"KMG",$i,1;$_=sprintf$i,$_}@F[1..3];$_=join"\t",@F,$/'
####
/dev/dsk/c0t1d0s1 1.2G 795.7M 382.2M 68% /usr
/dev/dsk/c0t1d0s3 239.7M 43.5M 172.2M 21% /var
/dev/dsk/c0t1d0s0 414.6M 182.8M 190.3M 49% /home
##
##
df -k|perl -ape'map{while(1024<$_){$_>>=10;my$i++}$_.=substr"KMG",$i,1}@F[1..3];$_=join"\t",@F,$/'
Output:
/dev/dsk/c0t1d0s1 1G 795M 382M 68% /usr
/dev/dsk/c0t1d0s3 239M 43M 172M 21% /var
/dev/dsk/c0t1d0s0 414M 182M 190M 49% /home