I don't "build", I extract. I used awk's substr() function, but it have been "cut -c13,14". Better still is the method below.

Please use [code] tags rather than changing font or size.

ps -eaf|grep "oracleTRLV (LOCAL=NO)"

oracle 1769 1 0 15:24:13 ? 0:00 oracleTRLV (LOCAL=NO)

Whoa! Which characters do you want? I don't think it's 13 and 14. And can you be sure that what you want is always in the same columns?

It would be better to read fields rather than characters. Which field (or part of a field) do you want?

Code:

a: oracle
b: 1769
c: 1
d: 0
e: 15:24:13
f: ?
g: 0:00
h: oracleTRLV (LOCAL=NO)

Presumably you want part of either e or g. I'd guess it's g.

You can read each field into a separate variable:

Code:

ps -eaf |
 while read user pid c d e f g command
 do
    ## get the minutes from $g
    temp=${g%:*}
    mins=${temp##*:}
    if [ ${mins#0} -gt 12 ]
    then
      kill $pid  ## you may need to add a signal
    fi
 done

It's not a tutorial, but there are many simple scripts you should be able to understand.