Re: How to run a GNAT program without starting a terminal session

["Dan'l Miller" <optikos@verizon.net>]

On Wednesday, July 18, 2018 at 4:41:41 PM UTC-5, Bill Findlay wrote:
> On 18 Jul 2018, Dan'l Miller wrote
> (in article<7500349d-e358-4c10-b4ec-6e95d44221af@googlegroups.com>):
> >
> > ... Or in fewer words, ...
> >
> > Btw, MacOS happens to have a (historically) BSD kernel (that is now somewhat
> > heavily modified), but MacOS, especially as the personality presented in
> > userspace, is truly a rather divergent not-terribly-Unix OS called Dylan.
> > Anyone who thinks that Dylan must conform to traditions of BSD Unix needs to
> > remember that BSD Unix itself is a rather divergent OS diverging away from
> > 1970s System III AT&T Unix, and that BSD Unix doesn't conform to all the
> > conventions of System III AT&T Unix either.
> 
> https://unix.stackexchange.com/questions/1489/is-mac-os-x-unix#1490
> 
> -- 
> Bill Findlay

Yeah, and MacOS has XQuartz for legacy compatibility with XWindow11-era antiquity.  MacOS didn't go so far as •removing• their legacy backwards compatibility with legacy Unix antiquity.  But so much of MacOS is Unix-esque reinterpretation.  MacOS still has the ghost of Unix-past antiquity, but not of the ghost of Unix/Linux present, and likely not the ghost of Linux future (because even Linux is charting an overtly divergent course from Unix (e.g., systemd)).

Take for example launchd in https://developer.apple.com/library/archive/documentation/MacOSX/Conceptual/BPSystemStartup/Chapters/DesigningDaemons.html#//apple_ref/doc/uid/10000172i-SW4-BBCBHBFB 

launchd daemon is unique to MacOS:
https://en.wikipedia.org/wiki/Launchd

Note that launchd is Unix-esque in its general look & feel, but launchd is not any of {systemd, cron, init scripts} that are accepted in Unix/Linux cannon.

Another 1 of the 4 categories is XPC.  XPC again is very Unix-esque but has no direct equivalent in any other flavor of Unix or Linux, because XPC is bolted deeply onto Grand Central Dispatch (which again is vaguely Unixy* but unique to MacOS and iOS).

* Had Grand Central Dispatch appeared in BSD-world or SystemV-world during the 1980s or early 1990s, it would be part of the Unix-world cannon, but it didn't so it isn't.