1 SC2175
koalaman edited this page 2016-01-25 19:43:11 -08:00

Quote this invalid brace expansion since it should be passed literally to eval

Problematic code:

eval echo {1..$n}

Correct code:

eval "echo {1..$n}"

Rationale:

Using eval somecommand {1..$n} depends both on bash silently failing to interpret the brace expansion, and on it passing failing brace expansions literally.

Rather than depending on these questionable features (which already behave differently in other shells), use the explicit, predictable way of passing values literally: quoting.

Exceptions:

None.