Of course it is. Bash isn't a shell well suited to scripting at all IMHO and should be avoided at all costs.

I suspect you are on an AIX system (btw. always say which system you work on - they all differ in some or other subtle regard and the answer you get might not work on your particular OS) and then "sh" is just a link to a ksh88. I am gonna use that as a basis for the script.

Your script will not work with "case"s like you did in the static version, but with a simple consistency check:

First, we read the output of "db2ilist" into an array:

Code:

#!/bin/ksh

typeset -i iCnt=0
typeset    chInstance=""
typeset -u chUInst=""
typeset -i iSelect=0
typeset    chSelect=""

(( iCnt = 1 ))
db2ilist | while read chInstance ; do
     achInstName[$iCnt]="$chInstance"
     (( iCnt += 1 ))
done

We now have an array with all the instance names. No we will use this to display a list of them along with a choice:

Code:

tput clear
print - "Enter the corresponding number to start the instance:\n"
(( iCnt = 1 ))
while [ $iCnt -le ${#achInstName[*]} ] ; do
     chUInst="${achInstName[$iCnt]}"
     printf "%2d)  %15s\n" "$iCnt" "$chUInst"
     (( iCnt += 1 ))
done
print - "\n\n      Enter your pick (0 to abort) ==>"
read chSelect

Now that we have displayed the menu and gotten some user response in "$chSelect", we have to make sure the pick is valid - an integer and within the range of our array.

the first test is if the text entered is an integer number at all - only digits 0-9, nothing else. We throw these digits out and if anything remains the users pick was invalid. Otherwise we copy this to a predefined integer variable.

The next test is if it is a "0", which means "Abort" - we exit.

Then a test, if it is between 1 and the maximum index of our array - if no, we complain and exit (start over?) if yes, we have a valid answer and continue.

Code:

if [ "$(print - $chSelect | tr -d '0-9')" != "" ] ; then
     print -u2 "Error: only the given numbers or 0 as input allowed." 
     exit 1
else
     iSelect=$chSelect
fi

if [ $iSelect -eq 0 ] ; then
     print -u2 "User selected abort, exiting..."
     exit 0
fi

if [ $iSelect -le ${#achInstName[*]} ] ; then
     . /dbhome/${achInstName[$iSelect]}/sqllib/db2profile
     db2 get instance
else
     print -u2 "Error: User entered an invalid pick number. Exiting."
     exit 1
fi

exit 0

I hope everything is well understandable from my comments. some of the not-so-obvious devices explained:

"${#arrayname[*]}" expands to the number of elements in the array.

"typeset -u" declares a variable which content is automatically converted to upper case upon load. Sort-of a built-in "toupper()" function.

I hope this helps.

bakunin