build@students1804:~/NetworksLab2018AU/messenger/linux_server$ cmake .
-- The C compiler identification is GNU 7.3.0
-- The CXX compiler identification is GNU 7.3.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/build/NetworksLab2018AU/messenger/linux_server
build@students1804:~/NetworksLab2018AU/messenger/linux_server$ make
Scanning dependencies of target server_linux
[ 50%] Building C object CMakeFiles/server_linux.dir/main.c.o
/home/build/NetworksLab2018AU/messenger/linux_server/main.c: In function ‘add_client’:
/home/build/NetworksLab2018AU/messenger/linux_server/main.c:31:28: warning: format ‘%d’ expects argument of type ‘int’, but argument 2 has type ‘size_t {aka long unsigned int}’ [-Wformat=]
     printf("clients count %d\n", clients_count);
                           ~^
                           %ld
/home/build/NetworksLab2018AU/messenger/linux_server/main.c: In function ‘handle_client’:
/home/build/NetworksLab2018AU/messenger/linux_server/main.c:117:25: warning: cast from pointer to integer of different size [-Wpointer-to-int-cast]
     int client_socket = (int) arg;
                         ^
/home/build/NetworksLab2018AU/messenger/linux_server/main.c: In function ‘main’:
/home/build/NetworksLab2018AU/messenger/linux_server/main.c:178:76: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]
             int code = pthread_create(&client_thread, NULL, handle_client, (void*) client_socket);
                                                                            ^
/home/build/NetworksLab2018AU/messenger/linux_server/main.c:138:14: warning: unused parameter ‘argc’ [-Wunused-parameter]
 int main(int argc, char *argv[]) {
              ^~~~
/home/build/NetworksLab2018AU/messenger/linux_server/main.c:138:26: warning: unused parameter ‘argv’ [-Wunused-parameter]
 int main(int argc, char *argv[]) {
                          ^~~~
[100%] Linking C executable server_linux
CMakeFiles/server_linux.dir/main.c.o: In function `main':
main.c:(.text+0x7a5): undefined reference to `pthread_create'
collect2: error: ld returned 1 exit status
CMakeFiles/server_linux.dir/build.make:94: recipe for target 'server_linux' failed
make[2]: *** [server_linux] Error 1
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/server_linux.dir/all' failed
make[1]: *** [CMakeFiles/server_linux.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2