need simple script to split a variable 1

[dans45]

Hello,
I'm working on a simple korn shell script to combine a couple of variables and insert a period '.' between the characters in one of the variables.
Example of what i want in my script:
SN=1234567
I want to create a variable valued as 1234.567
SN1=`${SN:0:4}`
which I thought would set SN1 to 1234
SN2=`${SN:4}`
which I thought would set SN1 to 567
but these do not work as I get"the specified substition is not valid for this command".

Thanks for your help. I'm tired of guessing at this.

 

[sbrews]

You are not doing anything wrong. The commands, as you have them in your example, are correct. The problem is your shell. I get the same error whenever I try to do most types of parameter expansion with ksh.

If you have access to a linux box, try the above under a bash shell and you will see that it works as expected.

I have not found a fix for this under ksh - but then again I havent really looked either.

scott

 

[SPguru]

Make sure you are using ksh93. I use dtksh (which uses ksh93) when using the ${var:X:y} syntax.