Convert to lower/upper case on the command line

Verified Environment

What to do

The ‘^’ operator converts lowercase letters matching pattern to uppercase; the ‘,’ operator converts matching uppercase letters to lowercase. The ‘^^’ and ‘,,’ expansions convert each matched character in the expanded value;

https://www.gnu.org/software/bash/manual/bash.html#Shell-Parameter-Expansion

val="ABC"
echo ${val,,}

val="abc"
echo ${val^^}

Verified Environment

What to do

• tolower
• toupper

echo ABC | awk '{print tolower($0)}'

echo abc | awk '{print toupper($0)}'

Verified Environment

What to do

\L Turn the replacement to lowercase until a \U or \E is found,

\U Turn the replacement to uppercase until a \L or \E is found,

https://www.gnu.org/software/sed/manual/sed.html#The-_0022s_0022-Command

echo ABC | sed -e 's/\(.*\)/\L\1/'

echo abc | sed -e 's/\(.*\)/\U\1/'

Verified Environment

What to do

[:lower:] all lower case letters

[:upper:] all upper case letters

https://man7.org/linux/man-pages/man1/tr.1.html

echo ABC | tr '[:upper:]' '[:lower:]'

echo abc | tr '[:lower:]' '[:upper:]'

Verified Environment

What to do

• ToLower()
• ToUpper()

"ABC".ToLower()

"abc".ToUpper()