2 files changed, 46 insertions(+), 20 deletions(-)

M Makefile
M netpower.c

@@ 1,4 1,4 @@
-CFLAGS := -Wall -Wpedantic
+CFLAGS := -Wall -Wpedantic -Os
 
 netpower: netpower.c config.h
 	$(CC) $(CFLAGS) -o $@ $<

@@ 1,4 1,5 @@
 #include <netdb.h>
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>


@@ 8,20 9,12 @@
 
 #include "config.h"
 
-int main(int argc, char *argv[])
-{
-	if (argc < 2) {
-		fprintf(stderr, "Usage: %s <n|f|c|q>\n", argv[0]);
-		exit(EXIT_FAILURE);
-	}
-
-	char action = argv[1][0];
-
-	if (action != 'n' && action != 'f' && action != 'c' && action != 'q') {
-		fprintf(stderr, "Invalid action: %c\n", action);
-		exit(EXIT_FAILURE);
-	}
+/* 4 extra bytes for the two escape characters (), the action character, and
+ * the carriage return (\r) */
+static const size_t BUF_SIZE = sizeof(PASSWORD) + 4;
 
+int create_socket()
+{
 	int sockfd;
 	struct addrinfo *result, *rp;
 	struct addrinfo hints = {


@@ 57,23 50,56 @@ int main(int argc, char *argv[])
 
 	freeaddrinfo(result);
 
-	char buf[16];
-	sprintf(buf, "%s%c\r", PASSWORD, action);
+	return sockfd;
+}
 
-	int buflen = strnlen(buf, 16);
-	if (write(sockfd, buf, buflen) != buflen) {
+void send_command(int sockfd, char action)
+{
+	char buf[BUF_SIZE];
+	sprintf(buf, "%s%c\r", PASSWORD, action);
+	if (write(sockfd, buf, BUF_SIZE) != BUF_SIZE) {
 		fprintf(stderr, "partial/failed write\n");
 		exit(EXIT_FAILURE);
 	}
 
-	memset(buf, 0, 16);
-	ssize_t nread = read(sockfd, buf, 16);
+	memset(buf, 0, BUF_SIZE);
+	ssize_t nread = read(sockfd, buf, BUF_SIZE);
 	if (nread == -1) {
 		perror("read");
 		exit(EXIT_FAILURE);
 	}
 
 	printf("%s\n", buf);
+}
+
+int is_valid_action(char action)
+{
+	switch (action) {
+	case 'n': /* ON */
+	case 'f': /* OFF */
+	case 'c': /* CYCLE */
+	case 'q': /* QUERY */
+		return 1;
+	default:
+		return 0;
+	}
+}
+
+int main(int argc, char *argv[])
+{
+	if (argc < 2) {
+		fprintf(stderr, "Usage: %s <n|f|c|q>\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	char action = argv[1][0];
+	if (!is_valid_action(action)) {
+		fprintf(stderr, "Invalid action: %c\n", action);
+		exit(EXIT_FAILURE);
+	}
+
+	int sockfd = create_socket();
+	send_command(sockfd, action);
 
 	exit(EXIT_SUCCESS);
 }