Re: Shell Expansion

[Chet Ramey]

On 4/14/21 9:15 AM, Greg Wooledge wrote:

> As for why bash chooses one over the other -- who knows?  

"The syntax of the shell command language has an ambiguity for expansions
beginning with "$((", which can introduce an arithmetic expansion or a
command substitution that starts with a subshell. Arithmetic expansion has
precedence; that is, the shell shall first determine whether it can parse
the expansion as an arithmetic expansion and shall only parse the expansion
as a command substitution if it determines that it cannot parse the
expansion as an arithmetic expansion."

https://pubs.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_06_03

--
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU    chet@case.edu    http://tiswww.cwru.edu/~chet/