Re: Tightening up specification of /bin/sh
Zack Weinberg wrote:
> > According to POSIX they shouldn't ignore the value in the
> > environment. At least ash seems to get this right:
> My reading of the XPG/4 page is that shells are allowed to honor or
> ignore it as they see fit. Therefore, this is a case where my
> proposal triggers. Ash honors the value in the environment, but bash,
> pdksh, AT&T ksh, and /bin/sh from three different proprietary Unix
> clones all ignore it. Therefore, under my proposal, ash is buggy.
> If POSIX says explicitly that it must be honored, that's news to me.
Hmm... As I read page 123 (Shell Command Language, Variables)
shells can't ignore the value in the environment:
"Variables shall be initialized from the environment ..."
"The following variables shall affect the execution of the
However at page 416-417 (sh, Environment Variables) they can:
"The following environment variables shall affect the execution
"IFS ... Implementations may ignore the value of IFS in the
environment at the time sh is invoked, treating IFS as if it were
I asked about this on the firstname.lastname@example.org mailing
list, but didn't got any answer.