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lang-bash
-nwith no operand lead to, for example, "error: -n requires an operand"? Does this question deserve to be posted as a new question?testimplementations (including Bash's) actually do return a distinct falsy status for an error, i.e. 0 for true, 1 for false and 2 for error. It's just that both 1 and 2 are falsy as far as shell conditionals are concerned, so one often doesn't get to see the difference. It'd need explicitly looking at the value of$?. Not that there's any invalid arguments here in this case (and anyway,[ -n ]is true), but you could try e.g.[ x x ]or similar. e.g.bash -c '[ x x ]; echo $?'prints2.