Linda, On Sunday 22 January 2006 13:16, Linda Walsh wrote:
I'm not quite sure what list or lists would address this issue, but when installing packages, it seems I have to install libraries (and utilities) for many packages I don't use, just because of a library linkage. With the library, though, the package may included a run-time daemon or other nonsense that doesn't get used in my local config.
It might be slightly more on-topic on the SuSE-Programming-E list.
...
Does linux understand the concept of run-time loadable libraries, where if you don't use a feature, the library doesn't need to be present? Only if you try to use one of the "extended" features, would an attempt be made to load the run-time library.
Almost all programs dynamically link at least some of their libraries and it is a transparent operation that the programmer need not concern themselves with. However, program-mediated linking and loading is not transparent and requires effort on the part of the programmer and so is not so often used.
Programs could automatically what libraries were present at runtime and enable/disable certain feature sets.
It's possible, but not common.
Is this possible in the normal Linux setup? If it is, why don't I see it used more often? Delayed-load libraries are common features on big-iron Unix, as well as being present even in Windows since at least 98 if not earlier.
There's a difference between on-demand link editing and on-demand loading. On Unix (-like) systems, transparent dynamic linking is common and free to application programmers. On-demand loading of the code pages comes "for free" as part of the page-oriented virtual memory system. Only non-transparent, program-mediated dynamic link editing where the absence of a library can be adapted to by the program requires work from the programmer and is not so commonly implemented.
Thanks, Linda
Randall Schulz -- God is a Black Lesbian.