CodingGuidelines: spell Arithmetic Expansion with $(($var))

POSIX wants shells to support both "N" and "$N" and requires them to yield the same answer to $((N)) and $(($N)), but we should aim for portability in a case like this, especially when the price we pay to do so is so small, i.e. a few extra dollars. Signed-off-by: Junio C Hamano <gitster@pobox.com>

Junio C Hamano committed Sep 22, 2010 at 12:15 UTC 055467dd4ae7fac2cf3149352710a5ee64b2138c

1 file changed +4

Documentation/CodingGuidelines

@@ -43,6 +43,10 @@ For shell scripts specifically (not exhaustive):

44 - We use Arithmetic Expansion $(( ... )).

46 + - Inside Arithmetic Expansion, spell shell variables with $ in front

47 + of them, as some shells do not grok $((x)) while accepting $(($x))

48 + just fine (e.g. dash older than 0.5.4).

49 +

50 - No "Substring Expansion" ${parameter:offset:length}.

52 - No shell arrays.