* -z instead of actually checking how many arguments you got passed and trusting the end user if they do something weird like pass an empty string to your program
* echo instead of printf
* `print_and_execute sdk install java $DEFAULT_JAVA_VERSION` who asked you to install things?
* `grep -h "^sdk use" "./prepare_$fork.sh" | cut -d' ' -f4 | while read -r version; do` You're seriously grepping shell scripts to determine what things you should install?
* Unquoted variables all over the place.
* Not using mktemp to hold all the temporary files and an exit trap to make sure they're cleaned up in most cases.
* #!/bin/bash instead of #!/usr/bin/env bash
* [ instead of [[
* -z instead of actually checking how many arguments you got passed and trusting the end user if they do something weird like pass an empty string to your program
* echo instead of printf
* `print_and_execute sdk install java $DEFAULT_JAVA_VERSION` who asked you to install things?
* `grep -h "^sdk use" "./prepare_$fork.sh" | cut -d' ' -f4 | while read -r version; do` You're seriously grepping shell scripts to determine what things you should install?
* Unquoted variables all over the place.
* Not using mktemp to hold all the temporary files and an exit trap to make sure they're cleaned up in most cases.