OPTIMIZE: replace read with printf

[andyneff]

printf -v var_name '%s' "${value}" # %s is important here to prevent escaping

appears to be 400% faster than

read -r -d '' var_name <<< "${value}"

If there are no side effects, everything that can and uses read and can be replaced with printf

• Verify speed on mac
• Verify speed on windows
• Verify speed on linux

[andyneff]

Does not work for arrays until bash 4.1

printf -v x[0] '%s' foo

[andyneff]

100x faster on windows for variable
2.5x faster on windows for array element
2x faster on linux for array elements
8x faster on linux for variables
5x faster on darling (only works for variables)
20x faster on macOS bash 3.2 (only works for variables)