Lets use the power of Bash here, ${variable^^} (the carrot symbol, two times)
Example of changing the case from lower to upper:
[email protected]:~$ myvar=codetryout
[email protected]:~$
[email protected]:~$ echo $myvar
codetryout
[email protected]:~$
[email protected]:~$ echo ${myvar^^}
ELIB
[email protected]:~$ This is very useful, for example when you want to process any user input, regardless of its case.
[email protected]:~$ read userinput
yes
[email protected]:~$ [[ ${userinput^^} == YES ]] && echo YES
YES
[email protected]:~$ read userinput
Yes
[email protected]:~$ [[ ${userinput^^} == YES ]] && echo YES
YES
[email protected]:~$ read userinput
YES
[email protected]:~$ [[ ${userinput^^} == YES ]] && echo YES
YES