[oi-dev] [discuss] Re: basis for better collaboration on illumos and OpenIndiana: small circle, Big circle

[Henk Langeveld]

On 02/18/2014 10:45 PM, Jim Klimov wrote:
>    I have yet to notice any functional-equivalency downsides
>    of old sh vs. ksh (or bash for that matter), although the
>    memory footprint comparison was often cited as a difference.

As one of the original advocates for including ksh93 in Solaris,
I did at one point list the risks of breaking existing shell scripts.
(I don't have a copy of that, could be in the original RFEs)

Major points were:

* Most any /bin/sh script should just work in ksh93, as the Bourne
   shell feature set is limited, and ksh93 is a superset of that.

* ksh scripts relying on shell arithmetic can fail in ksh93, which
   by default calculates intermediate results in floating point.

Not really functional: Running a snippet of code in ksh93 is typically
faster than any of bourne, bash or ksh88.

Henk