Chen-Lung Wu, I forund that I needed to do several steps to compile c code and make a shared library. Here is what I did: (for HelloWorld example) files HelloWorld.java, HelloWorldImp.c, Main.java 1. run javac on HelloWorld.java, and javah on this (as instruced in the example) 2. compile the C code with gcc gcc -fPIC -I/usr/local/java/include -I/usr/local/java/include/genunix -c HelloWorldImp.c gcc -shared -W1,-soname,libhello.so.1 -o libhello.so.1.0 HelloWorldImp.o create the links to the library with version numbers: ln -s libhello.so.1.0 libhello.so.1 ln -s libhello.so.1 libhello.so information from the linux gcc HOWTO file. Hope this helps. Laurel Watts -- Laurel A. Watts NIST 838.01 325 Broadway Boulder, CO 80303 (303) 497-7418 ---------------------------------------------------------------------- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]