diff --git a/main.c b/main.c
index 3ed705a..6ab63e3 100644
--- a/main.c
+++ b/main.c
@@ -1,19 +1,22 @@
+// Gerardo Marx 24/09/2026
+// gpio command tool
+//
 #include <stdio.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <string.h>
+
+// prototype functions
+int gpio_export(const char *gpio);
+int gpio_direction(int gpio, const char *direction);
+int gpio_write(int gpio, int value);
 
 int main(int argc, char *argv[]){
-	int fd;
-	// export
-	fd = open("/sys/class/gpio/chip0/export", O_WRONLY);
-	if(fd<0)
-	{
-		perror("Error opening the GPIO path");
-		return -1;
-	}
 
-	write(fd,"17",2);
-	close(fd);
+	int fd;
+	char pin[] = "17";
+	gpio_export(pin); 
+	
 	// pin direction
 	fd = open("/sys/class/gpio/chip0/gpio17/direction", O_WRONLY);
 	if(fd<0)
@@ -64,3 +67,17 @@ int main(int argc, char *argv[]){
 	return 0;
 }
 
+// comple functions
+//
+// gpio_export
+int gpio_export(const char *gpio){
+	int fd;
+	fd = open("/sys/class/gpio/chip0/export", O_WRONLY);
+	if(fd<0){
+		perror("Error opening the GPIO path");
+		return -1;
+	}
+	write(fd,"17",2);
+	close(fd);
+	return 0;
+}