Hi, I'm having some trouble when i try to compile the Blowfish C algorithm source code. Whenever i type this command: gcc BLOWFISH.C I get this result: [charles@linux1 Blowfish]$ gcc BLOWFISH.C /usr/lib/gcc/i386-redhat-linux/4.0.0/../../../crt1.o(.text+0x18): In function `_start': : undefined reference to `main' /tmp/ccsc34vS.o(.eh_frame+0x11): undefined reference to `__gxx_personality_v0' collect2: ld returned 1 exit status However, when you specify to only compile and assemble and not link, everything works smoothly. Because of this i am pretty sure the problem lies with the linker. I am running fedora core 4 test 2 with gcc 4.0.0 I have tried locating the files, but to no avail. Any suggestions to charlesawake@xxxxxxxxx Thanks, Charles Barry