Purpose: collect information, pointers, etc. regarding issues relating to Tcl and dynamic libraries.
Dynamic libraries - in Windows known as DLLs and in Unix often called shared libraries - are bodies of C code compiled and linked in a manner that make it possible for the code to be read into memory and made a part of running processes.
In Tcl, if the appropriate C code is provided, and the code is compiled properly, one can make use of Tcl's load command to load a dynamic library into an interpreter creating one or more new tcl commands.
Configuring Source code issues
When configuing tcl, one seems to need to make certain that one specifies --enable-shared and not specify --disable-load .
Anyone know why the flags are two different words? Is shared and load really two different conditions?
DGP Yes, those configuration options specify two different things. --enable-shared (default) vs. --disable-shared determines whether or not the Tcl library you build is a shared library or a static library. --enable-load (default) vs. --disable-load determines whether or not the Tcl library you build supports a working load command.
LV When you say "[...] supports a working load command", do you mean that --disable-load results in a Tcl library which does not recognize load as a valid command?
DGP No. When a --disable-load configuration of the Tcl library is built, it contains a load command that is the functional equivalent of the command [error "dynamic loading is not currently available on this system"]
LV However, the --enable-shared/--disable-shared , at least if present, would indicate that the extension (or, in the case of Tcl itself, the base Tcl library) that is generated will be able to be loaded. Right?
DGP I don't understand the rest of your question.
MSW Nope. You can load an extension into a static interpreter, but only if load is functionally available. Whether or not your tcl library is static or dynamic itself doesn't matter.
LV Now I am confused. Are you saying that it doesn't matter how an extension is built, as long as one has a functional load command?
MSW Nope, I'm saying that you can load any dynamic library as long as a functional load command is there, no matter whether tcl itself is a dynamic lib or linked statically (which --enable/--disable-shared governs). It doesn't matter how tcl itself is built as long as you can load others stuff dynamically...
Stubs issues
See Stubs, Extension Stubs Tables, and Writing extensions for stubs and pre-stubs Tcl.
[Are there any wiki or non-wiki web references which could be inserted here that discuss the approrpriate calls one must make in a library for this?]
[What other wiki and non-wiki references would be useful here?]
What about Direct Shared Library Use for Tcl9?