When the command echo $ outputs 1, which of the following statements is true?

Question

Options

• AIt is the process ID of the echo command.
• BIt is the process ID of the current shell.
• CIt is the exit value of the command executed immediately before echo.
• DIt is the exit value of the echo command.

• A
  10% (3)
• B
  3% (1)
• C
  71% (22)
• D
  16% (5)

Explanation

In bash, $? is a special variable that holds the exit status of the most recently completed command - so when echo $? outputs 1, that 1 was set by whatever command ran just before echo, making C correct. Option A is wrong because $? has nothing to do with process IDs; $$ (double dollar) is the variable for the current shell's PID. Option B is wrong for the same reason - $$ stores the shell's PID, not $?. Option D is wrong because echo itself typically exits with 0 (success); by the time echo finishes, its own exit status would overwrite $?, but we're reading $? as the argument to echo, which captures the prior command's status before echo runs.

Memory tip: Think of ? as the shell asking "how did that go?" - it stores the answer from the last command (0 = success, non-zero = failure), and it gets refreshed after every command completes.

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