Path: utzoo!mnetor!uunet!epiwrl!epimass!jbuck From: jbuck@epimass.EPI.COM (Joe Buck) Newsgroups: comp.unix.wizards Subject: Re: SVR3.0 vs BSD4.3 Message-ID: <2025@epimass.EPI.COM> Date: 22 Mar 88 18:01:56 GMT References: <12414@brl-adm.ARPA> <4361@megaron.arizona.edu> <7499@brl-smoke.ARPA> <2423@bsu-cs.UUCP> <7514@brl-smoke.ARPA> Reply-To: jbuck@epimass.EPI.COM (Joe Buck) Organization: Entropic Processing, Inc., Cupertino, CA Lines: 65 In article <7514@brl-smoke.ARPA> gwyn@brl.arpa (Doug Gwyn (VLD/VMB) ) writes: >In article <2423@bsu-cs.UUCP> dhesi@bsu-cs.UUCP (Rahul Dhesi) writes: >> [ what's missing from Sys V ] >> job control (stop/restart jobs, get status of jobs and know >> one is stopped for tty input) > >As I mentioned, the System V equivalent is "shell layers", which is >not quite as nice from the user's perspective but it sure disrupts the >system internals less than the 4BSD approach. shl isn't anywhere NEAR as nice from the user's perspective as job control and isn't an adequate replacement. This is the number one reason that I, and a vast number of other users, will not consider a Sys V environment. Windows are also not an adequate replacement; I use both windows and job control. You can explain why I'm technically foolish to have this attitude. But I use it and I like it. If the internal implementation is inelegant, that's unfortunate; I'd tolerate slight changes in the user interface if it would result in cleaner internals, but we do the internals to get the nice user interface, not the other way around! >> support for multiple command interpreters with #! as first line of script > >This is totally unnecessary; if all scripts are executed by a Bourne >shell, it is easy to simulate the #! feature, in fact to generalize >on it. Nevertheless I think AT&T may be adding this kludge to the >kernel exec code in a future release, alas. The reason Dennis Ritchie invented #! (that's right, it's not a Berkeleyism) was for the Pascal p-code interpreter. It wasn't originally designed for csh shell scripts at all! It makes programs like Larry Wall's "perl" much more wonderful as well. While it's unsafe to write a set-uid shell script, it's perfectly safe to write a set-uid perl script, and this can only be done with #!. There are things #! gives you that you can't get any other way, and implementing it isn't ugly at all -- it simply generalizes the concept of the "magic number" at the beginning of an executable. csh is not the reason for #!. >> dbm library--fast /etc/passwd and /usr/lib/news/history access etc. > >There are other ways to speed up /etc/passwd access that don't have >the drawback of maintaining a separate index file. A good, standard >ISAM would be useful, but dbm ain't it. Here I agree with you. dbm sucks, in many ways. I was extremely peturbed once when I found you can't have two dbm databases open in the same program -- I ended up forking off a second program to do part of the job. >> context diffs from diff > >This could be added easily enough, and I considered adding it to my >System V emulation package but decided it wasn't particularly useful. Context diffs are the safest way to transmit small source code changes in a distributed environment, and are easier both for programs and for people to deal with. Oh, by the way, Sys V versions of many utilities are vastly superior: lint and make especially come to mind. -- - Joe Buck {uunet,ucbvax,sun,}!epimass.epi.com!jbuck Old Internet mailers: jbuck%epimass.epi.com@uunet.uu.net