split network code into extra file

.gitignore

@@ -0,0 +1 @@
+bin/

Makefile

@@ -3,7 +3,7 @@ BIN=bin
 all: dirs command
 
 command: command.c
-	gcc -o ${BIN}/command command.c
+	gcc -o ${BIN}/command network.c command.c
 
 .PHONY: clean dirs
 clean:

command.c

@@ -2,52 +2,10 @@
 #include <stdio.h>
 #include <string.h>
 
-#include <sys/socket.h>
+#include "network.h"
-#include <sys/types.h> // BSD compatible
-#include <arpa/inet.h>
-#include <unistd.h>
-
-#include <errno.h>
-#include <netdb.h>
-
-#define SERVER "::1"
-#define PORT 49000
-
-#define COMMAND_BUFFER 256
-
-char* printable(char *str) {
-	char *ret = strdup(str);
-
-	for (int i = strlen(ret); i >= 0; i--) {
-		if (ret[i] == '\r' || ret[i] == '\n') {
-			ret[i] = '\0';
-		}
-	}
-
-	return ret;
-}
-
-void sendCommand(int sock, char *cmd) {
-	char bytesToSend[COMMAND_BUFFER];
-	memset(bytesToSend, 0, COMMAND_BUFFER);
-
-	strcpy(&bytesToSend[0], "CMND");
-	strcpy(&bytesToSend[5], cmd);
-
-	int numBytesSend = send(sock, bytesToSend, 5 + strlen(cmd), 0);
-	if (numBytesSend >= 0) {
-		//printf("Send %d bytes to %s:%d: %s\n", numBytesSend, SERVER, PORT, printable(bytesToSend));
-	} else {
-		fprintf(stderr, "Failed to send message to %s:%d (%d): %s", SERVER, PORT, errno, strerror(errno));
-		exit(EXIT_FAILURE);
-	}
-}
 
 int main(int argc, char *argv[]) {
-	int xplaneSocket;
+	int xPlaneSocket;
-	struct sockaddr_in6 xplaneAddress;
-
-	int err;
 
 	// check argument
 	if (argc != 2) {
@@ -55,29 +13,18 @@ int main(int argc, char *argv[]) {
 		exit(EXIT_FAILURE);
 	}
 
-	// create socket
+	// network
-	xplaneSocket = socket(AF_INET6, SOCK_DGRAM, 0);
+	xPlaneSocket = connectXPlane(SERVER, PORT);
-	if (xplaneSocket == -1) {
+	if (xPlaneSocket < 0) {
-		fprintf(stderr, "Error creating socket (%d): %s\n", errno, strerror(errno));
-		exit(EXIT_FAILURE);
-	}
-
-	// prepare address struct
-	xplaneAddress.sin6_family = AF_INET6;
-	xplaneAddress.sin6_port = htons(PORT);
-	inet_pton(AF_INET6, SERVER, &xplaneAddress.sin6_addr.s6_addr);
-
-	// connect to xplane
-	err = connect(xplaneSocket, (struct sockaddr *)&xplaneAddress, sizeof(xplaneAddress));
-	if (err) {
-		fprintf(stderr, "Error connecting %s:%d (%d): %s\n", SERVER, PORT, err, gai_strerror(err));
 		exit(EXIT_FAILURE);
 	}
 
 	// send payload
-	sendCommand(xplaneSocket, argv[1]);
+	if (sendCommand(xPlaneSocket, argv[1]) < 0) {
+		exit(EXIT_FAILURE);
+	}
 
 	// bye bye (and no, I don't care about error anymore; I'll exit anyway?!)
-	close(xplaneSocket);
+	disconnectXPlane(xPlaneSocket);
 	exit(EXIT_SUCCESS);
 }

network.c

@@ -0,0 +1,75 @@
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+
+#include <sys/socket.h>
+#include <sys/types.h> // BSD compatible
+#include <arpa/inet.h>
+#include <unistd.h>
+
+#include <errno.h>
+#include <netdb.h>
+
+#include "network.h"
+
+char* printable(char *str) {
+	char *ret = strdup(str);
+
+	for (int i = strlen(ret); i >= 0; i--) {
+		if (ret[i] == '\r' || ret[i] == '\n') {
+			ret[i] = '\0';
+		}
+	}
+
+	return ret;
+}
+
+int sendCommand(int sock, char *cmd) {
+	char bytesToSend[COMMAND_BUFFER];
+	memset(bytesToSend, 0, COMMAND_BUFFER);
+
+	strcpy(&bytesToSend[0], "CMND");
+	strcpy(&bytesToSend[5], cmd);
+
+	int numBytesSend = send(sock, bytesToSend, 5 + strlen(cmd), 0);
+	if (numBytesSend >= 0) {
+		//printf("Send %d bytes to %s:%d: %s\n", numBytesSend, SERVER, PORT, printable(bytesToSend));
+		return numBytesSend;
+	} else {
+		fprintf(stderr, "Failed to send message to %s:%d (%d): %s", SERVER, PORT, errno, strerror(errno));
+		return -1;
+	}
+}
+
+int connectXPlane(char *addr, int port) {
+	int xPlaneSocket;
+	struct sockaddr_in6 xPlaneAddress;
+
+	int err;
+
+	// create socket
+	xPlaneSocket = socket(AF_INET6, SOCK_DGRAM, 0);
+	if (xPlaneSocket == -1) {
+		fprintf(stderr, "Error creating socket (%d): %s\n", errno, strerror(errno));
+		return -1;
+	}
+
+	// prepare address struct
+	xPlaneAddress.sin6_family = AF_INET6;
+	xPlaneAddress.sin6_port = htons(PORT);
+	inet_pton(AF_INET6, SERVER, &xPlaneAddress.sin6_addr.s6_addr);
+
+	// connect to xPlane
+	err = connect(xPlaneSocket, (struct sockaddr *)&xPlaneAddress, sizeof(xPlaneAddress));
+	if (err) {
+		fprintf(stderr, "Error connecting %s:%d (%d): %s\n", SERVER, PORT, err, gai_strerror(err));
+		return -1;
+	}
+
+	return xPlaneSocket;
+}
+
+int disconnectXPlane(int sock) {
+	// bye bye (and no, I don't care about error anymore; I'll exit anyway?!)
+	close(sock);
+}

network.h

@@ -0,0 +1,9 @@
+#define SERVER "::1"
+#define PORT 49000
+
+#define COMMAND_BUFFER 256
+
+char* printable(char *str);
+int sendCommand(int sock, char *cmd);
+int connectXPlane(char *addr, int port);
+int disconnectXPlane(int sock);