I have a small a program that should start a 2nd Thread. the problem is that, when try to make an executable file of this program using make. I get :

 engine@ubuntu:~/Desktop/Lecture$ make thread cc thread.c -o thread thread.c: In function ‘main’: thread.c:10:2: error: unknown type name ‘pthread’ .............

here is my code :

#include <stdio.h> #include <stdlib.h> #include <pthread.h> #include <errno.h> void *func(void*); int main(){ pthread tid; if (pthread_create(&tid,NULL,fun,NULL)!= 0 ){ printf("error by _ pthread \n"); } printf ( "thread output1 \n"); sleep(1); return EXIT_SUCCESS; } void *fun(void* data){ printf("thread output2 \n") }

I don't think that program is wrong, it maybe the way I'm running the make command ?

any Idea why do I get this. thanks in advance for your help

2

2 Answers

Did you forget to link a dynamic library?

cc thread.c -o thread -lpthread

Further errors:

  • type of pthread is pthread_t
  • you misspelled fun and func
  • no semicolon in function after printf
1

According to the manual page for pthread_create and some sample code around the internet, the first parameter is a pointer to pthread_t, not pthread. Try that:

pthread_t tid;