$ cat primes.pl0 
const max = 100;
var arg, ret;

procedure isprime;
var i;
begin
	ret := 1;
	i := 2;
	while i < arg do
	begin
		if ( arg / i * i ) = arg then
		begin
			ret := 0;
			i := arg
		end;
		i := i + 1
	end
end;

procedure primes;
begin
	arg := 2;
	while arg < max do
	begin
		call isprime;
		if  ret = 1  then write arg;
		arg := arg + 1
	end
end;

call primes
.

frodo ~/pl0c $ ./pl0c primes.pl0  > p.c
frodo ~/pl0c $ gcc p.c
frodo ~/pl0c $ ./a.out 
2
3
5
7
11
13
17
19
23
29
31
37
41
43
47
53
59
61
67
71
73
79
83
89
97

frodo ~/pl0c $ git diff *.c
diff --git a/pl0c.c b/pl0c.c
index f416730..7044009 100644
--- a/pl0c.c
+++ b/pl0c.c
@@ -33,6 +33,7 @@
 #define TOK_VAR                'V'
 #define TOK_PROCEDURE  'P'
 #define TOK_CALL       'c'
+#define TOK_WRITE       'w'
 #define TOK_BEGIN      'B'
 #define TOK_END                'E'
 #define TOK_IF         'i'
@@ -184,6 +185,8 @@ ident(void)
                return TOK_PROCEDURE;
        else if (!strcmp(token, "call"))
                return TOK_CALL;
+       else if (!strcmp(token, "write"))
+               return TOK_WRITE;
        else if (!strcmp(token, "begin"))
                return TOK_BEGIN;
        else if (!strcmp(token, "end"))
@@ -679,6 +682,12 @@ statement(void)
                        cg_call();
                expect(TOK_IDENT);
                break;
+        case TOK_WRITE:
+            expect(TOK_WRITE);
+            if ( type == TOK_IDENT)
+                aout("printf(\"%%d\\n\",%s);",token);
+            expect(TOK_IDENT);
+            break;
        case TOK_BEGIN:
                cg_symbol();
                expect(TOK_BEGIN);
@@ -827,6 +836,8 @@ main(int argc, char *argv[])
        readin(argv[1]);
        startp = raw;
 
+        aout("#include <stdio.h>\n");
+
        initsymtab();