Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!bcm!uhnix2!uhnix1!sugar!peter From: peter@sugar.UUCP (Peter da Silva) Newsgroups: comp.sys.amiga Subject: Re: Unix on the Amiga Message-ID: <1968@sugar.UUCP> Date: 12 May 88 01:08:23 GMT References: <8805042034.AA15057@cory.Berkeley.EDU> <1932@sugar.UUCP> <146@elgar.UUCP> Organization: Sugar Land UNIX - Houston, TX Lines: 30 In article <146@elgar.UUCP>, ford@elgar.UUCP writes: > In article <1932@sugar.UUCP> peter@sugar.UUCP (Peter da Silva) writes: > >The problem is that if you're going to emulate UNIX on the Amiga (see that > >there Subject: line?) you need to emulate fork(). There's no question about > >it. It's one of the core system calls. > 99 percent of all forks could be vforks instead. 99% of all fork/exec pairs could be system()s or popen()s instead, too. But they're not. Because on UNIX the ground call is fork(). The cases where you need the semantics of fork() can't be fixed up this way. > Vfork is better > because it doesn't actually create a whole new process, just another > thread in the old memory space. vfork() is a kludge. By implementing a copy-on-write fork instead you can get all the efficiency of vfork() and all the generality of fork(). > Incedentally, the System V Interface Definition encourages the use of > system() rather than fork(). This is an especially good idea on > AmigaDos... This I agree entirely with, and I am still mystified as to why Aztec bothered to implement fexec at all. Actually, there's something to be said for implementing Execute() on UNIX... -- -- Peter da Silva `-_-' ...!hoptoad!academ!uhnix1!sugar!peter -- "Have you hugged your U wolf today?" ...!bellcore!tness1!sugar!peter -- Disclaimer: These aren't mere opinions, these are *values*.