I received an off-list reply about this, with permission to forward it to the list...
------- Forwarded Message From: "M. Levinson" <mlev...@users.sourceforge.net> Date: Sat, 15 Jul 2017 08:10:44 -0400 To: Robert Elz <k...@munnari.oz.au> Subject: Re: external versions of sh built-in utilities For what little it's worth, here's where this silly requirement can be found (in case you're still looking for it): http://pubs.opengroup.org/onlinepubs/9699919799.2016edition/utilities/V3_chap01 .html#tag_17_06 However, all of the standard utilities, including the regular built-ins in the table, but not the special built-ins described in Special Built-In Utilities, shall be implemented in a manner so that they can be accessed via the exec family of functions as defined in the System Interfaces volume of POSIX.1-2008 and can be invoked directly by those standard utilities that require it (env, find, nice, nohup, time, xargs). ------- End of Forwarded Message Another off list reply suggested that if this requirement exists (which now it is obvious it does) then that would be a (another) perfect excuse to ignore POSIX. kre
