From ea212325cc4962742ec8d9ddff39ddbf815fd85e Mon Sep 17 00:00:00 2001
From: Gerardo Marx <gmarx_cc@itmorelia.edu.mx>
Date: Wed, 30 Sep 2026 19:36:31 -0600
Subject: [PATCH] gpio_unexport function

---
 main.c | 39 ++++++++++++++++++++++++++++-----------
 1 file changed, 28 insertions(+), 11 deletions(-)

diff --git a/main.c b/main.c
index aebda6f..f525e3c 100644
--- a/main.c
+++ b/main.c
@@ -15,6 +15,7 @@ int gpio_export(const char *gpio);
 int gpio_direction(const char *gpio, const char *direction); // this function
 int gpio_write(const char *gpio, const char *value); // write function
 int gpio_read(const char *gpio); //read function
+int gpio_unexport(const char *gpio);
 
 int main(int argc, char *argv[]){
 	int fd;
@@ -47,16 +48,8 @@ int main(int argc, char *argv[]){
 	gpio_export(pin); 
 	gpio_direction(pin, dir);
 	gpio_write(pin, val);
+	gpio_unexport(pin);
 	
-	// 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);
 }
 
 // comple functions
@@ -66,7 +59,7 @@ 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");
+		perror("Error opening the GPIO path during export");
 		return -1;
 	}
 	write(fd,gpio,strlen(gpio));
@@ -101,7 +94,7 @@ int gpio_write(const char *gpio, const char *value){
 			"/sys/class/gpio/chip0/gpio%s/value", gpio);
 	fd = open(path, O_WRONLY);
 	if(fd<0){
-		perror("Error opening the GPIO path");
+		perror("Error opening the GPIO path during write");
 		return -1;
 	}
 	if(write(fd,value, strlen(value)) < 0) {
@@ -113,3 +106,27 @@ int gpio_write(const char *gpio, const char *value){
 	close(fd);
 	return 0;
 }
+
+// gpio read
+int gpio_read(const char *gpio); //read function
+
+
+
+
+// unexport
+int gpio_unexport(const char *gpio){
+	int fd;
+	fd = open("/sys/class/gpio/chip0/unexport", O_WRONLY);
+	if(fd<0)
+	{
+		perror("Error opening the GPIO path during unexport");
+		return -1;
+	}
+	if(write(fd,gpio, strlen(gpio)) < 0) {
+		perror("unexport");
+		close(fd);
+		return -1;
+	}
+	close(fd);
+	return 0;
+}