Linux C++ Error: Undefined Reference to 'Dlopen'

Linux c++ error: undefined reference to 'dlopen'

You have to link against libdl, add

-ldl

to your linker options

undefined reference to `dlopen'

Move autocheck.cpp so that it is before the libraries in your command. Libraries are only searched for things that need resolving in files that appear before them. So your command should look like this:

gcc autocheck.cpp -I/usr/lib/qt3/include -I/opt/kde3/include/  -fmessage-length=0 -O2 -Wall -D_FORTIFY_SOURCE=2 -fstack-protector -funwind-tables -fasynchronous-unwind-tables -lqt-mt -ldl -L/usr/lib/qt3/lib64 -o autocheck 

Undefined reference to 'dlsym' and 'dlopen'

Well, I found the answer, I needed -Wl,--no-as-needed flag before the -ldl. I had run across this flag before I asked the question, but apparently mistyped it because it hadn't worked for me.

I don't understand why the flag is needed, but the code does finish linking now.

A SO user here says that it has to do with recent (2013 as of the user's post) versions of gcc linking to --as-needed.

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