How to split input string into multiple variable - arrays

Question

I'm working on shell script and trying to split user input into multiple variable and use them at different places.
User input is not fixed so can't really assign fixed number of variable, input is separated by comma ,
./user_input.ksh -string /m01,/m02,/m03
#!/bin/ksh
STR=$2
function showMounts {
echo "$STR"
arr=($(tr ',' ' ' <<< "$STR"))
printf "%s\n" "$(arr[#]}"
for x in "$(arr[#]}"
do
free_space=`df -h "$x" | grep -v "Avail" | awk '{print $4}'`
echo "$x": free_space "$free_space"
done
#total_free_space = <total of $free_space>
#echo "$total_free_space"
}
Basically $STR* variable value is filesystem mount points
Host output if run separate df -h command
$ df -h /m01 | grep -v "Avail" | awk '{print $4}'
***Output***
150
Current problems:
(working)1. How to get free space available for each /m* using df -h?

Answer 1

Easiest thing to do is to use shell array here like this:
#!/bin/ksh
str='/m01,/m02,/m03'
arr=($(tr ',' ' ' <<< "$str"))
printf "%s\n" "${arr[#]}"
Output:
/m01
/m02
/m03
To read elements individually you can use:
"${arr[0]}"
"${arr[1]}"
...
Update: Here is your corrected script:
#!/bin/ksh
STR="$2"
arr=($(tr ',' ' ' <<< "$STR"))
printf "<%s>\n" "${arr[#]}"
for x in "${arr[#]}"; do
echo "$x"
free_space=`df -h "$x" | awk '!/Avail/{print $4}'`
echo "$free_space"
done

Answer 2

you can try,
#!/bin/ksh
STR=/m01,/m02,/m03
read STR1 STR2 STR3 <<<`echo $STR | awk 'BEGIN{FS=","; OFS=" "}{$1=$1; print}'`
echo $STR1 - $STR2 - $STR3
you get:
/m01 - /m02 - /m03

Answer 3

A variation on the theme:
# cat user_input.ksh
#!/bin/ksh
c=1
for i in $(echo ${#} | tr "," " ")
do
eval STR$c="$i"
((c=c+1))
done
printf "\$STR1 = %s; \$STR2 = %s; \$STR3 = %s; ...\n" "$STR1" "$STR2" "$STR3"
Which gives you:
# ksh ./user_input.ksh /m01,/m02,/m03,/m04
$STR1 = /m01; $STR2 = /m02; $STR3 = /m03; ...
Hope that helps..
--ab1

Answer 4

$ cat tst.sh
str='/m01,/m02,/m03'
IFS=,
set -- $str
for i
do
echo "$i"
done
$ ./tst.sh
/m01
/m02
/m03
Don't use all-upper-case for variable names unless you are going to export them (by convention and to avoid clashes with built in names like HOME, PATH, IFS, etc.).
For your overall script, you should simply be doing something like this:
df -h "${str//,/ }" | awk '/^ /{print $5, $3; sum+=$3} END{print sum}'
depending on what your df -h output looks like and what you're final output is supposed to be.