code to create thread in operating systems

void mainline (...)
{
struct phonebookentry *pbe;
pthread_attr_t tattr;
pthread_t helper;
int status;
pthread_create(&helper, NULL, fetch, &pbe);
/* do something else for a while */
pthread_join(helper, &status);
/* it's now safe to use result */


}
void fetch(struct phonebookentry *arg)
{
struct phonebookentry *npbe;
/* fetch value from a database */
npbe = search (prog_name)
if (npbe != NULL)
*arg = *npbe;
pthread_exit(0);
}
struct phonebookentry {
char name[64];
char phonenumber[32];
char flags[16];
}