4.1   Hello world in C

• A simple application composed of two programs
• Program hello.c, the main program

  #include <pvm3.h>
  
  main ()
  {
     int tid ; 
     char reply [100] ;
     
     printf ("I'm t%x\n", pvm_mytid ()) ;
     if (pvm_spawn("hello_other", (char**)0, 
                   0, "", 1, &tid) == 1)
     {
        pvm_recv (-1, -1) ;
        pvm_bufinfo (pvm_getrbuf (), (int*)0, 
                     (int*)0, &tid) ;
        pvm_upkstr(reply) ;
        printf (From t%x: %s\n", tid, reply) ;
     } else 
        printf ("Can't start hello_other\n") ;
     pvm_exit () ;
  }            
        

• 
  
  Program hello_other.c, the auxiliary program

  #include <pvm3.h>
  
  main ()
  {
     int ptid ; /* parent's tid */
     char buf [100] ;
     
     ptid = pvm_parent () ;
     strcpy (buf, "Hello world from ") ; 
     gethostname (buf+strlen(buf), 64) ;
     pvm_initsend (PvmDataDefault) ;
     pvm_pkstr (buf) ;
     pvm_send (ptid, 1) ;
     pvm_exit () ;
  }