1 files changed, 45 insertions, 34 deletions

diff --git a/pd_server.c b/pd_server.c
index d0b2315..b8ff6f0 100644
--- a/pd_server.c
+++ b/pd_server.c
@@ -1,6 +1,7 @@
 #include <stdio.h> 
 #include <stdlib.h> 
 #include <string.h>
+#include <assert.h>
 #include <unistd.h>
 #include <errno.h>
 #include <sys/types.h>
@@ -14,25 +15,33 @@ enum {
 }; 
 
 int pay(int a, int b) 
-{ 
-        if (a == COORPERATION && b == DEFECTION)    return 1; 
-        if (a == DEFECTION    && b == DEFECTION)    return 2; 
-        if (a == COORPERATION && b == COORPERATION) return 3; 
-        if (a == DEFECTION    && b == COORPERATION) return 4; 
+{
+	assert(a == COORPERATION || a == DEFECTION);
+	assert(b == COORPERATION || b == DEFECTION);
+
+	if (a == COORPERATION && b == DEFECTION)    return 1; 
+	if (a == DEFECTION    && b == DEFECTION)    return 2; 
+	if (a == COORPERATION && b == COORPERATION) return 3; 
+	if (a == DEFECTION    && b == COORPERATION) return 4; 
 
-        exit(EXIT_FAILURE); 
-} 
+	exit(EXIT_FAILURE); 
+}
 
 int
 main(int argc, char *argv[])
 {
-	int sock, player[2], read_fd;
+	int sock, player[2];
 	struct sockaddr_in serv_addr;
 	int port = 8068;
-	int rounds, i;
+	int a_payment = 0, b_payment = 0, rounds, i;
 	int optval = 1;
+	char *endptr;
 
-	rounds = atoi(argv[1]);
+	errno = 0;
+	if (argc < 2 || (rounds = strtol(argv[1], NULL, 10)) <= 0 || errno!=0) {
+		fprintf(stderr, "usage: %s number-of-rounds\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
 
 	sock = socket(AF_INET, SOCK_STREAM, 0);
 	if (sock < 0)
@@ -50,34 +59,36 @@ main(int argc, char *argv[])
 	}
 	listen(sock, 2);
 
-	for (i = 0; i < 2; ++i) {
-		player[i] = accept(sock, NULL, NULL);
-	}
-	int a_payment = 0, b_payment = 0;
-	for (i = 0; i < rounds; ++i) {
-		char a, b;
-		read(player[0], &a, 1);
-		read(player[1], &b, 1);
-
-		if (a != 'c' && a != 'd') {
-			printf("a sent incorrect char: %c\n", a);
-			continue;
-		}
-		if (b != 'c' && b != 'd') {
-			printf("b sent incorrect char: %c\n", b);
-			continue;
+	for (;;) {
+		for (i = 0; i < 2; ++i) {
+			player[i] = accept(sock, NULL, NULL);
 		}
+		for (i = 0; i < rounds; ++i) {
+			char a, b;
+			read(player[0], &a, 1);
+			read(player[1], &b, 1);
 
-                a_payment += pay(a, b); 
-                b_payment += pay(b, a); 
+			if (a != 'c' && a != 'd') {
+				printf("a sent incorrect char: %c\n", a);
+				continue;
+			}
+			if (b != 'c' && b != 'd') {
+				printf("b sent incorrect char: %c\n", b);
+				continue;
+			}
 
-                printf("A [%c]: %d Euro\tB [%c]: %d Euro\t\t\tA: %d\tB: %d\n", 
-                       a, pay(a, b), b, pay(b, a), a_payment, b_payment); 
+			a_payment += pay(a, b);
+			b_payment += pay(b, a);
 
-		write(player[0], &b, 1);
-		write(player[1], &a, 1);
+			printf("A [%c]: %d Euro\tB [%c]: %d Euro\t\t\t"
+			       "A: %d\tB: %d\n",
+			       a, pay(a,b), b, pay(b,a), a_payment, b_payment);
+
+			write(player[0], &b, 1);
+			write(player[1], &a, 1);
+		}
+		close(player[0]);
+		close(player[1]);
 	}
-	close(player[0]);
-	close(player[1]);
 	close(sock);
 }