>#else
>static int module_output(
> struct inode *inode, /* The inode read */
> struct file *file, /* The file read */
> char *buf, /* The buffer to put data to (in the user segment) */
> int len) /* The length of the buffer */
>#endif
>{
> static int finished = 0;
> int i;
> char message[MESSAGE_LENGTH+30];
> /* We return 0 to indicate end of file, that we have
> * no more information. Otherwise, processes will
> * continue to read from us in an endless loop. */
> if (finished) {
> finished = 0;
> return 0;
> }
> /* We use put_user to copy the string from the kernel's
> * memory segment to the memory segment of the process
> * that called us. get_user, BTW, is
> * used for the reverse. */
> sprintf(message, "Last input:%s", Message);
> for(i=0; i
> /* Notice, we assume here that the size of the message
> * is below len, or it will be received cut. In a real
> * life situation, if the size of the message is less
> * than len then we'd return len and on the second call
> * start filling the buffer with the len+1'th byte of the message. */
> finished = 1;
> return i; /* Return the number of bytes "read" */
>}
>/* This function receives input from the user when the
>* user writes to the /proc file. */
>#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
>static ssize_t module_input(
> struct file *file, /* The file itself */
> const char *buf, /* The buffer with input */
> size_t length, /* The buffer's length */
> loff_t *offset) /* offset to file - ignore */
>#else
>static int module_input(
> struct inode *inode, /* The file's inode */
> struct file *file, /* The file itself */
> const char *buf, /* The buffer with the input */
> int length) /* The buffer's length */
>#endif
>{
> int i;
> /* Put the input into Message, where module_output will later be able to use it */
> for (i=0; i
>#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,2,0)
> get_user(Message[i], buf+i);
> /* In version 2.2 the semantics of get_user changed,
> * it not longer returns a character, but expects a
> * variable to fill up as its first argument and a
> * user segment pointer to fill it from as the its second.
> *
> * The reason for this change is that the version 2.2
> * get_user can also read an short or an int. The way
> * it knows the type of the variable it should read
> * is by using sizeof, and for that it needs the
> * variable itself. */
>#else
> Message[i] = get_user(buf+i);
>#endif
> Message[i] = '\0'; /* we want a standard, zero terminated string */
