To compile gawk with dynamic extension support,
uncomment the definitions of DYN_FLAGS, DYN_EXP,
DYN_OBJ, and DYN_MAKEXP in the configuration section of
the Makefile. There are two definitions for DYN_MAKEXP:
pick the one that matches your target.
To build some of the example extension libraries, cd to the
extension directory and copy Makefile.pc to Makefile. You
can then build using the same two targets. To run the example
awk scripts, you'll need to either change the call to
the extension function to match the name of the library (for
instance, change "./ordchr.so" to "ordchr.dll" or simply
"ordchr"), or rename the library to match the call (for instance,
rename ordchr.dll to ordchr.so).
If you build gawk.exe with one compiler but want to build an extension library with the other, you need to copy the import library. Visual C uses a library called gawk.lib, while MinGW uses a library called libgawk.a. These files are equivalent and will interoperate if you give them the correct name. The resulting shared libraries are also interoperable.
To create your own extension library, you can use the examples as models,
but you're essentially on your own. Post to comp.lang.awk or
send electronic mail to ptjm@interlog.com if you have problems getting
started. If you need to access functions or variables which are not
exported by gawk.exe, add them to gawkw32.def and
rebuild. You should also add ATTRIBUTE_EXPORTED to the declaration
in awk.h of any variables you add to gawkw32.def.
Note that extension libraries have the name of the awk
executable embedded in them at link time, so they will work only
with gawk.exe. In particular, they won't work if you
rename gawk.exe to awk.exe or if you try to use
pgawk.exe. You can perform profiling by temporarily renaming
pgawk.exe to gawk.exe. You can resolve this problem
by changing the program name in the definition of DYN_MAKEXP
for your compiler.
On Windows32, libraries are sought first in the current directory, then in the directory containing gawk.exe, and finally through the PATH environment variable.