Bash - eval (Execute its argument)

eval is a bash builtin command that executes command by concatenating arguments.

eval [arg ...]

• The args are read and concatenated together into a single command, separating each with a <space>.
• This command is then read and executed by the shell

It exit status is returned as the value of eval. If there are no args, or only null arguments, eval returns 0.

• POSIX Programmer's Manual