Re: Q: shared libraries

In <594g38$b0c@cssun.mathcs.emory.edu> <johnl@informix.com> (Jonathan Leffler) wrote: : At the last time I looked (two or three years ago, I think, and well within : the current decade), SCO Unix did not have the plug-n-play shared libraries : available with SVR4 systems. Yes, it had shared libraries, but no, : Informix's code could not be built into SCO shared libraries. It required : major revamping of the Informix source code to allow it to work with the : restrictions of the SCO shared libraries. I'm not saying that the : reworking would not have been a good idea, but the resources were not : available to do it. : 1. I was talking about shared library in general. the first two reasons in my list (i.e. speeding up loading and reducing page consumption and job of paging) have nothing to do with p-n-p. I just followed an article on talking whether it is worth to use shared library for saving disk space by sacrificing easy of administration. What I tried to point out is, the real reasons shared libraries are valuable beyond saving disk space(of cause, the third and fourth reasons in my list need p-n-p). Yes, as David correct me, disk saving is also one of the very important advantage of it(on solaris 2.5, a "hello world" program would be size of over 100k instead of only less than 10k if linked as -Bstatic). 2. as a matter of fact, SCO support p-n-p shared library in this decade. i.e. both SCO 5.x OpenServer(1994) and SCO SVR4(95, i.e. formal UnixWare) support ELF p-n-p shared library(which is PIC and support all dlxxx() functions). In English, you still need to use words of "wasn't ..." and "hadn't ..." when telling a story just happended yesterday(as long as it is no longer true today). 3. p-n-p has nothing to do with system and not necessary to be in shared form. It can be an user level facility(even many systems support it by a bundled api and in form of shared library). Two examples are, Ultrix still not supports p-n-p shared library and its shared library is also as painful as SCO. However, Postgres95 supports object code p-n-p on Ultrix. Old Linux(i.e. before 1.1 i believe), also not support p-n-p shared library. Its shared library is more painful than both SCO and Ultrix. However, gnu dld 2.7 support non-shared p-n-p on it and had been widely used in perl5 world before the real p-n-p shared library become available (of cause, it become almost useless because later version of Linux already support svr4ish shared library p-n-p). Thus, even old SCO(i.e. SCO 3.2) doesn't bundle an object code p-n-p facility in shared library form, it is completely possible to support p-n-p on it(of cause, nobody want to do it for a going to be obsolete system -- by SCO 5.x or SCO svr4 ). : The situation may have changed -- if someone knows about it, I'm interested : to know about it. But SCO shared libraries were a pain in the posterior, : which is why I4GL does not yet supply them. Yes, the situation has changed at least for two years. But I am not suggesting change of I4GL. There are far too many things beyond that we expect from informix. : : Yours, : Jonathan Leffler (johnl@informix.com) #include <disclaimer.h> : : PS: Is your login name really guest? And are you really based in the : rmy.emory.edu domain? If not, kindly fix your mailer or news system to : inform us who you really are. It isn't as though you are talking rubbish : and need to be ashamed of yourself, unlike some people who scam this : newsgroup with completely off-topic articles. Yes, my login name _is_ 'guest' where I am doing the post. However, I am absolutly not based on rmy.emory.edu. I believe your news server get confused and put its own domain name on. please check with altavista or dejanews, you will see the 'From' or 'Sender' fields don't have domain names there. -g