codeaft@codeaft:~$ echo 'Hello, World!' | tr "[:lower:]" "[:upper:]"
HELLO, WORLD!

codeaft@codeaft:~$ echo 'HeLLo, WORLD!' | tr "[:upper:]" "[:lower:]"
hello, world!
codeaft@codeaft:~$ typeset -l lcase
codeaft@codeaft:~$ lcase="Hello, World!"
codeaft@codeaft:~$ echo $lcase
hello, world!

codeaft@codeaft:~$ typeset -u ucase
codeaft@codeaft:~$ ucase="Hello, World!"
codeaft@codeaft:~$ echo $ucase
HELLO, WORLD!
codeaft@codeaft:~$ s1="HeLLo, WORLD!"
codeaft@codeaft:~$ echo $s1
HeLLo, WORLD!

codeaft@codeaft:~$ echo ${s1,,}
hello, world!

codeaft@codeaft:~$ echo ${s1^^}
HELLO, WORLD!

codeaft@codeaft:~$ printf "Octal of 65535 = %o\n" 65535
Octal of 65535 = 177777

codeaft@codeaft:~$ printf "Hexadecimal of 65535 = %x\n" 65535
Hexadecimal of 65535 = ffff

codeaft@codeaft:~$ printf "Floating point in 65535 = %f\n" 65535
Floating point in 65535 = 65535.000000
codeaft@codeaft:~$ D2B=({0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1}{0..1})
codeaft@codeaft:~$ echo "Binary of 255 = "${D2B[255]}
Binary of 255 = 11111111

codeaft@codeaft:~$ echo "Decimal of 01AE = "$((0x01AE))
Decimal of 01AE = 430

codeaft@codeaft:~$ echo "Decimal of 11111111 = "$((2#11111111))
Decimal of 11111111 = 255

codeaft@codeaft:~$ echo "obase=2;255" | bc
11111111

codeaft@codeaft:~$ echo "ibase=2;11111111" | bc
255

codeaft@codeaft:~$ echo "obase=7;255" | bc
513

codeaft@codeaft:~$ echo "obase=16;255" | bc
FF
codeaft@codeaft:~$