counter in a variable - can it be done?

Shell Programming and Scripting
1

I have the following

for(( i=1; 1<=2; i++))
do
e1=123 n1=123
e2=456 n2=456
coord= $e1,$n1
echo "coordinate=$coord"
done
exit

this echos
coordinate=123,123

I need it to loop so:
loop1
coord=$e1,$n1
loop2
coord=$e2.$n2

then it echos:

coordinate=123,123
coordinate=456,456

I have been trying to write it like this:
coord=$e${i},$n${i}

but it doesn't work any ideas

Thanks

Gary

2

In Korn shell -- a personal favorite -- there are two ways of doing it both of which you have considered (I've changed the numbers a bit to make it clearer:

1 ) As an array

#!/bin/ksh

set -A e 123 456
set -A n 234 567

I=0

while [ $I -lt ${#e[*]} ]
do
    echo "coordinate=${e[$I]}, ${n[$I]}"
    (( I += 1 ))
done
exit

coordinate=123, 234
coordinate=456, 567

or using individual variables:

#/bin/ksh

e1=123; n1=234
e2=456; n2=567

for I in 1 2
do
    eval echo "coordinate=\$e$I, \$n$I"
done
exit

coordinate=123, 234
coordinate=456, 567

3

the latter nearly worked but just displayed
coordinate=$e1,$n1
coordinate=$e2,$n2

I need it to replace these with the actual values

4

It worked for me once I fixed the first line...

$ cat x
#!/usr/bin/ksh

e1=123; n1=234
e2=456; n2=567

for I in 1 2
do
    eval echo "coordinate=\$e$I, \$n$I"
done
exit
$ ./x
coordinate=123, 234
coordinate=456, 567
$