comp.databases.informix.4gl: Shared Libraries Information

Shared Libraries Informational A couple of posts recently talked about shared libraries. My understanding of a shared library was different than the one presented here. Chapter 8 of the Unix Programmer's Guide talks about the concept of shared libraries, and is an excellent resource about this topic. Mose UNIX vendors provide this manual, along with the UNIX Programmer's Reference, and the UNIX Users Reference Manual. This guide also covers several other topics such as LEX, YACC, cc, curses, and more. I highly recommend it for your book library. ( Prentice Hall, ISBN 0-13-940438-4 ATT version ) As evidenced from the posts, folks are confusing the idea of library usage and shared library usage. I think for the sake of brevity, the distinction is as follows: Library: - a collection of object files stored in a library, using the ar utility. Objects are compiled WITH the a.out for use at run time. Shared Library: - a library created with the mkshlib utility, for explicit use with compiled executables at run-time, that DO NOT have these lib routines compiled into the a.out. You could think of the shared lib concept similar to the use of DLL's in Windows. DLL is "dynamic linked library", and thus similar in concept. The merits of shared libraries used with any programming environement are something to be tested and evaluated on an individual site basis. When introducing something like shared libraries, consider the additional maintenance required. The regualar library concept is also something else to maintain, and can present additional overhead and complexity in application maintenance. Libraries can and should be maintained with a makefile, not shell scripts, to allow a simple and professional approach to their maintenance. I hope this helps clear up the confusion presented. Tim -- \\\\|// (O|O) ==============================---o00--(_)--00o---============================ Tim Schaefer tschaefe@gate.net http://www.gate.net/~tschaefe People who don't make anything cain't buy anything...never forget that. -HRP =============================================================================