Which command shows environmental variables within the shell?

• A. env
• B. printenv
• C. getenv
• D. set

Answer: (D)

Inspecting the shell's variable state requires understanding the difference between shell variables and environment variables. Environment variables are the ones exported to child processes, while shell variables stay local to the current session. The built-in command set, when run with no arguments, prints every shell variable and function, including those exported to the environment. This provides a complete view of what the shell knows and has defined, which is why it’s the best way to see variables within the shell itself. In contrast, env (and printenv) show only environment variables that would be inherited by child processes, not the full set of shell-local variables. The term getenv isn’t a standard standalone shell command in most shells. So using set gives the most comprehensive snapshot of the shell’s current state.