Compile simple hello world ZeroMQ C example, compile flags? - c

Question

Trying to compile the example hello_world.c from the zeromq tutorial:
http://zguide.zeromq.org/page:all#Ask-and-Ye-Shall-Receive
Pretty sure I have everything installed in OSX Mountain Lion.
clang -Wall hwserver.c -o hwserver
gives me an error:
Undefined symbols for architecture x86_64:
"_zmq_bind", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_ctx_new", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_msg_close", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_msg_data", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_msg_init", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_msg_init_size", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_msg_recv", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_msg_send", referenced from:
_main in hwserver-OgrEe6.o
"_zmq_socket", referenced from:
_main in hwserver-OgrEe6.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)
I'm not the most experienced in C. Not sure if I sure be adding a compiler flag for the zmq dylib or headers or my $PATH being off.
in /usr/local/lib:
libzmq.3.dylib
libzmq.a
libzmq.dylib
libzmq.la
and in /usr/local/include:
zmq.h
zmq_utils.h
and echo $PATH:
/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/usr/local/lib/:/usr/local/include/

Answer 1

You list the ZeroMQ libraries in your question, but you do not actually link with them. Change the command line to this:
clang -Wall hwserver.c -o hwserver -L/usr/local/lib -lzmq
Explanation of the extra arguments:
-L/usr/local/lib tells the linker to add a path (/usr/local/lib) to the library search path.
-lzmq tells the library to link with the zmq library.
The $PATH environment variable have nothing to do with this, it just tells the shell where to look for commands.