github.com/afumu/libc@v0.0.6/musl/src/ipc/ftok.c (about)

     1  #include <sys/ipc.h>
     2  #include <sys/stat.h>
     3  
     4  key_t ftok(const char *path, int id)
     5  {
     6  	struct stat st;
     7  	if (stat(path, &st) < 0) return -1;
     8  
     9  	return ((st.st_ino & 0xffff) | ((st.st_dev & 0xff) << 16) | ((id & 0xffu) << 24));
    10  }