Bad substitution error while working with substring

Shell Programming and Scripting
1

Hi I'm using ksh.
And i'm trying to get the substring like below.
but giving the following error

 
#!/bin/ksh
foo=teststring
bar=${foo:0:5}
echo $bar

And the error is

./sbstr_test.sh[4]: bar=${foo:0:5}: bad substitution

what is wrong in this script. Please correct me

---------- Post updated at 06:11 PM ---------- Previous update was at 05:21 PM ----------

Even i tried with the following but of no use

#!/bin/ksh
foo=teststring
bar=${$foo:0:5}
echo $bar

and getting the error same as above

2

What are you trying to do here???

3

Why not simply bar="$foo:0:5" ?

4

Most probably you're using ksh88 (or pdksh), but the syntax above is available in ksh93.
Note that zsh and bash support the ${varname:n:m} notation too.

Edit: I suppose the OP wants to extract a substring from the value of the variable:

% foo=teststring
% printf '%s\n' "${foo:0:5}"
tests

Note that in this case you can use also:

% printf '%.5s\n' "$foo"
tests

or:

% printf '%s\n' "${foo%${foo#?????}}"
tests