I tried to convert a lowercase string to uppercase and assign it to a variable using the following code
The script is written in .tn extension
set y a12 y_up=$( tr '[A-Z]' '[a-z]' <<< $y) echo $y echo $y_up But I am getting the error
invalid command name "A-Z" while executing "A-Z" invoked from within "y_up=$( tr '[A-Z]' '[a-z]' <<< $y) " How can I convert this?
BASH 4+ version has native way to convert sting to upper case:
str="Some string here" upperStr="${str^^}" Below Works, Try this.
bash-3.2$echo lower to upper | tr '[:lower:]' '[:upper:]' LOWER TO UPPER # To Save in the variable use below var=$(echo lower to upper | tr '[:lower:]' '[:upper:]') 
This should work:
$ y="Foo Bar Baz" $ y_up=$(tr '[A-Z]' '[a-z]' <<< $y) $ echo $y_up foo bar baz 
tr command should look like: tr '[a-z]' '[A-Z]'Starting from Bash 5.1, you can also use the @U parameter transformation to convert all lowercase characters in parameter expansions into uppercase characters.
For example:
s="hello, wORLd!" echo "${s@U}" # HELLO, WORLD! And for your exact case:
y="a12" y_up="${y@U}" echo $y # a12 echo $y_up # A12 This also saves you from making an extra call to tr , which would incur a slight performance overhead since tr is not a shell builtin and therefore requires making syscalls to fork() and exec() to execute.
setdoes not what you think it does...