shell/bash generate random alphanumeric string

bash.generate.random.alphanumeric.string.sh

#!/bin/bash
# bash generate random alphanumeric string

randomized() { cat /dev/urandom | tr -dc ${2:-"A-HJ-NP-Za-km-z2-9%^&*()_+?><~;"} | fold -w ${1:-32} | head -n 1; }

# LC_CTYPE=C supports macos. It is done in a subshell so as not to pollute the environment.
random_string() { echo $(export LC_CTYPE=C; randomized ${@}); }

random_hex() { random_string ${1:-4} 'a-f0-9'; }
random_hexu() { random_string ${1:-4} 'A-F0-9'; }

# bash Version 4 UUID
UUID4() { local uuid=($(random_hexu 8) $(random_hexu 4) $(random_hexu 4) $(random_hexu 4) $(random_hexu 12)); echo $(IFS='-'; echo "${uuid[*]}"); }