I'm looking for a way in Korn shell to zero fill (or space fill) the output from df so that it will sort properly.

"Raw" output from df -k:

df -k

Filesystem            kbytes    used   avail capacity  Mounted on
/dev/vx/dsk/rootvol  4131866 3593302  497246    88%    /
/proc                      0       0       0     0%    /proc
fd                         0       0       0     0%    /dev/fd
mnttab                     0       0       0     0%    /etc/mnttab
swap                 19891520     144 19891376     1%    /var/run
swap                 19913552   22176 19891376     1%    /tmp
/dev/vx/dsk/u01      112302757 30833295 80346435    28%    /u01
/dev/vx/dsk/node@1     96975    4977   82301     6%    /global/.devices/node@1
/dev/vx/dsk/node@2     96975    4988   82290     6%    /global/.devices/node@2
/dev/vx/dsk/stkdg/s03
                     1047527424 60483821 925353439     7%    /s03
/dev/vx/dsk/stkdg/s02
                     1048576000 266754165 732957997    27%    /s02
/dev/vx/dsk/sandg/s01
                     355923968 322572197 31422792    92%    /global/s01

df -k | grep / | awk '{ print $5}' | sort -r

92%
88%
7%
6%
6%
28%
27%
1%
1%
0%
0%
0%

92%
88%
28%
27%
 7%
 6%
 6%
 1%
 1%
 0%
 0%
 0%

The output you are getting is not "incorrect". It is actually correct with the flags you are giving sort.
You have to tell sort that you are sorting numbers and not text.

:> df -k | grep / | awk '{print $5}' | sort -gr
100%
7%
2%
0%
0%

df -k | awk '/[/]/ { print $5}' | sort -rn

vgersh99,

Cool! This seems to work. Thanks for the help.

System Shock,

>>A quick look at the man pages would've given you the answer.

I don't think so:

df -k | grep / | awk '{print $5}' | sort -gr
sort: illegal option -- g
usage: sort [-cmu] [-o output] [-T directory] [-S mem] [-z recsz]
        [-dfiMnr] [-b] [-t char] [-k keydef] [+pos1 [-pos2]] files...

And another one:

df -k | 
  while read fs kb us av ca mo; do 
    case $ca in 
      *[0-9]% ) printf "%s\n" "$ca";;
    esac
done | sort -rn

..well, obviously you are running at the very least a different version of sort because it works for me; you didn't specify an OS or sort version. In any case, it still stands that a quick look at the man pages of whatever OS and sort version you are using would've given you the answer.