error cathcer in all fds

main.c

@@ -8,7 +8,7 @@ int main(int argc, char *argv[]){
 	fd = open("/sys/class/gpio/chip0/export", O_WRONLY);
 	if(fd<0)
 	{
-		perror("Error opening the GPIO export path");
+		perror("Error opening the GPIO path");
 		return -1;
 	}
 
@@ -16,21 +16,41 @@ int main(int argc, char *argv[]){
 	close(fd);
 	// pin direction
 	fd = open("/sys/class/gpio/chip0/gpio17/direction", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO path");
+		return -1;
+	}
 	write(fd,"out",3);
 	close(fd);
 	
 	// pin value to 1
 	fd = open("/sys/class/gpio/chip0/gpio17/value", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO path");
+		return -1;
+	}
 	write(fd,"1",1);
 	close(fd);
 	sleep(1);
 	// pin valu to 0
 	fd = open("/sys/class/gpio/chip0/gpio17/value", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO path");
+		return -1;
+	}
 	write(fd,"0",1);
 	close(fd);
 	sleep(1);
 	// unexport
 	fd = open("/sys/class/gpio/chip0/unexport", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO path");
+		return -1;
+	}
 	write(fd,"17",2);
 	close(fd);