Eclipse C Development in Linux: Undefined reference to 'pthread _ create'

You need to add the compilation option:-lpthread

GCC thread. C-o thread-lpthread

If eclipse is developed

Method 1:

Eclipse
The solution is as follows:
Method 1: Project-> properties-> C/C ++ build-> Settings-> gcc C ++ linker-> Libraries
Add pthread to libraries (-l ).
Add crypto to libraries search path (-l ).

Method 2: Right-click the project and choose Properties> C/C ++ build> builder settings.

Select the automatically generated makefile option.

Open makefile in the debug folder

Manually add compilation options in makefile:

Gcc-o "sockthreadclient" $ (objs) $ (user_objs) $ (libs)-Lpthread