--- stack/symbols.c	2003/08/05 09:09:51	1.4
+++ stack/symbols.c	2003/08/08 14:20:49	1.5
@@ -1,4 +1,5 @@
 #include "stack.h"
+#include "messages.h"
 
 /* Print newline. */
 extern void nl(environment *env)
@@ -304,8 +305,7 @@
 /* Clear stack */
 extern void clear(environment *env)
 {
-  while(env->head->type != empty)
-    toss(env);
+  env->head= new_val(env);
 }
 
 /* Forgets a symbol (remove it from the hash table) */
@@ -1463,3 +1463,127 @@
   push_cstring(env, new_string);
 }
 
+/* "fork" */
+extern void sx_666f726b(environment *env)
+{
+  push_int(env, fork());
+}
+
+/* "waitpid" */
+extern void sx_77616974706964(environment *env)
+{
+
+  if(env->head->type==empty) {
+    printerr("Too Few Arguments");
+    env->err= 1;
+    return;
+  }
+
+  if(CAR(env->head)->type!=integer) {
+    printerr("Bad Argument Type");
+    env->err= 2;
+    return;
+  }
+
+  push_int(env, waitpid(CAR(env->head)->content.i, NULL, 0));
+  swap(env); toss(env);
+}
+
+
+/* Discard the top element of the stack. */
+extern void toss(environment *env)
+{
+  if(env->head->type==empty) {
+    printerr("Too Few Arguments");
+    env->err= 1;
+    return;
+  }
+  
+  env->head= CDR(env->head); /* Remove the top stack item */
+}
+
+
+/* Quit stack. */
+extern void quit(environment *env)
+{
+  int i;
+
+  env->head= new_val(env);
+
+  if (env->err) return;
+  for(i= 0; i<HASHTBLSIZE; i++) {
+    while(env->symbols[i]!= NULL) {
+      forget_sym(&(env->symbols[i]));
+    }
+    env->symbols[i]= NULL;
+  }
+
+  env->gc_limit= 0;
+  gc_maybe(env);
+
+  words(env);
+
+  if(env->free_string!=NULL)
+    free(env->free_string);
+  
+#ifdef __linux__
+  muntrace();
+#endif
+
+  exit(EXIT_SUCCESS);
+}
+
+
+/* List all defined words */
+extern void words(environment *env)
+{
+  symbol *temp;
+  int i;
+  
+  for(i= 0; i<HASHTBLSIZE; i++) {
+    temp= env->symbols[i];
+    while(temp!=NULL) {
+#ifdef DEBUG
+      if (temp->val != NULL && temp->val->gc.flag.protect)
+	printf("(protected) ");
+#endif /* DEBUG */
+      printf("%s ", temp->id);
+      temp= temp->next;
+    }
+  }
+}
+
+
+/* Only to be called by itself function printstack. */
+void print_st(environment *env, value *stack_head, long counter)
+{ 
+  if(CDR(stack_head)->type != empty)
+    print_st(env, CDR(stack_head), counter+1);
+  printf("%ld: ", counter);
+  print_val(env, CAR(stack_head), 0, NULL, stdout);
+  printf("\n");
+}
+
+
+/* Prints the stack. */
+extern void printstack(environment *env)
+{
+  if(env->head->type == empty) {
+    printf("Stack Empty\n");
+    return;
+  }
+
+  print_st(env, env->head, 1);
+}
+
+
+extern void copying(environment *env)
+{
+  printf(license_message);
+}
+
+
+extern void warranty(environment *env)
+{
+  printf(warranty_message);
+}