I have written the following lines to get the last character of a string:
str=$1 i=$((${#str}-1)) echo ${str:$i:1}
It works for abcd/
abcd/
Try:
"${str:$((${#str}-1)):1}"
For e.g.:
someone@mypc:~$ str="A random string*"; echo "$str" A random string* someone@mypc:~$ echo "${str:$((${#str}-1)):1}" * someone@mypc:~$ echo "${str:$((${#str}-2)):1}" g