From: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Date: Tue, 8 Dec 2009 17:58:24 +0000 (-0200)
Subject: Added buffer length to proc entry.
X-Git-Url: http://git.cascardo.info/?p=cascardo%2Fkernel%2Fsamples%2F02.char%2F.git;a=commitdiff_plain;h=67446b4c4a1ee4df194203d80ed3077d08c52c88

Added buffer length to proc entry.
---

diff --git a/helloc.c b/helloc.c
index 9f983a2..b0271df 100644
--- a/helloc.c
+++ b/helloc.c
@@ -6,6 +6,8 @@
 /* Needed for copying to/from user space */
 #include <asm/uaccess.h>
 #include <linux/slab.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>");
@@ -108,6 +110,27 @@ static struct file_operations helloc_fops = {
 	.write = helloc_write,
 };
 
+static int hello_len_show(struct seq_file *seq, void *data)
+{
+	struct message *msg = seq->private;
+	seq_printf(seq, "%d\n", msg->len);
+	return 0;
+}
+
+static int hello_proc_open(struct inode *ino, struct file *filp)
+{
+	return single_open(filp, hello_len_show, hello_message[0]);
+}
+
+static struct file_operations hello_proc_fops = {
+	.owner = THIS_MODULE,
+	.open = hello_proc_open,
+	.llseek = seq_lseek,
+	.read = seq_read,
+	.release = seq_release,
+};
+
+
 /* the device number and the char device struct */
 static dev_t dev;
 static struct cdev *cdev;
@@ -145,6 +168,7 @@ out:
 
 static int __init helloc_init(void)
 {
+	struct proc_dir_entry *hello_pde;
 	int r;
 	r = helloc_alloc();
 	if (r)
@@ -167,7 +191,12 @@ static int __init helloc_init(void)
 	r = cdev_add(cdev, dev, DEVICE_NUMBER);
 	if (r)
 		goto out_add;
+	hello_pde = proc_create("hello_len", 0666, NULL, &hello_proc_fops);
+	if (!hello_pde)
+		goto out_pde;
 	return 0;
+out_pde:
+	cdev_del(cdev);
 out_add:
 	/* release memory allocated to the cdev device */
 	kfree(cdev);
@@ -181,6 +210,7 @@ out_alloc2:
 
 static void __exit helloc_exit(void)
 {
+	remove_proc_entry("hello_len", NULL);
 	/* remove the chardev from the system */
 	cdev_del(cdev);
 	/* release the device number allocated */