error catcher in all fds

main.c

@@ -6,10 +6,10 @@ int main(int argc, char *argv[]){
 	int fd; 
 	// export
 	fd = open("/sys/class/gpio/chip0/export", O_WRONLY);
-    if(fd<0)
+	if(fd<0)
 	{
 		perror("Error opening the GPIO export path");
-        return -1;
+		return -1;
 	}
 
 	write(fd,"17",2);
@@ -17,16 +17,36 @@ int main(int argc, char *argv[]){
 
 	// pin direction
 	fd = open("/sys/class/gpio/chip0/gpio17/direction", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO export path");
+		return -1;
+	}
+
+
+	
 	write(fd,"out",3);
 	close(fd);
 	
 	// pin value
 	fd = open("/sys/class/gpio/chip0/gpio17/value", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO export path");
+		return -1;
+	}
+
 	write(fd,"1",1);
 	close(fd);
 
 	//pin
 	fd = open("/sys/class/gpio/chip0/gpio17/value", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO export path");
+		return -1;
+	}
+
 	write(fd,"0",1);
 	close(fd);
 	sleep(1);
@@ -34,6 +54,12 @@ int main(int argc, char *argv[]){
 
 	// unexport
 	fd = open("/sys/class/gpio/chip0/unexport", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO export path");
+		return -1;
+	}
+
 	write(fd,"17",2);
 	close(fd);