内核模块编好后，其他程序该如何调用呢？

mudga

比如我这里有个书上的例子：

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/*
*  print_string.c - Send output to the tty we're running on, regardless if it's
*  through X11, telnet, etc.  We do this by printing the string to the tty
*  associated with the current task.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/sched.h>        /* For current */
#include <linux/tty.h>                /* For the tty declarations */
#include <linux/version.h>        /* For LINUX_VERSION_CODE */

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Peter Jay Salzman");

static void print_string(char *str)
{
        struct tty_struct *my_tty;

        /*
         * tty struct went into signal struct in 2.6.6
         */
#if ( LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,5) )
        /*
         * The tty for the current task
         */
        my_tty = current->tty;
#else
        /*
         * The tty for the current task, for 2.6.6+ kernels
         */
        my_tty = current->signal->tty;
#endif

        /*
         * If my_tty is NULL, the current task has no tty you can print to
         * (ie, if it's a daemon).  If so, there's nothing we can do.
         */
        if (my_tty != NULL) {

                /*
                 * my_tty->driver is a struct which holds the tty's functions,
                 * one of which (write) is used to write strings to the tty.
                 * It can be used to take a string either from the user's or
                 * kernel's memory segment.
                 *
                 * The function's 1st parameter is the tty to write to,
                 * because the same function would normally be used for all
                 * tty's of a certain type.  The 2nd parameter controls whether
                 * the function receives a string from kernel memory (false, 0)
                 * or from user memory (true, non zero).  The 3rd parameter is
                 * a pointer to a string.  The 4th parameter is the length of
                 * the string.
                 */
                ((my_tty->driver)->write) (my_tty,        /* The tty itself */
                                           0,        /* Don't take the string
                                                   from user space        */
                                           str,        /* String                 */
                                           strlen(str));        /* Length */

                /*
                 * ttys were originally hardware devices, which (usually)
                 * strictly followed the ASCII standard.  In ASCII, to move to
                 * a new line you need two characters, a carriage return and a
                 * line feed.  On Unix, the ASCII line feed is used for both
                 * purposes - so we can't just use \n, because it wouldn't have
                 * a carriage return and the next line will start at the
                 * column right after the line feed.
                 *
                 * This is why text files are different between Unix and
                 * MS Windows.  In CP/M and derivatives, like MS-DOS and
                 * MS Windows, the ASCII standard was strictly adhered to,
                 * and therefore a newline requirs both a LF and a CR.
                 */
                ((my_tty->driver)->write) (my_tty, 0, "\015\012", 2);
        }
}

static int __init print_string_init(void)
{
        print_string("The module has been inserted.  Hello world!");
        return 0;
}

static void __exit print_string_exit(void)
{
        print_string("The module has been removed.  Farewell world!");
}

module_init(print_string_init);
module_exit(print_string_exit);

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这个print_string我该如何调用呢？谢谢

mudga

对了，这个列子在2.6.19.2上有些错误

  ((my_tty->driver)->write) (my_tty,        /* The tty itself */
                                           0,        /* Don't take the string
                                                   from user space        */
                                           str,        /* String                 */
                                           strlen(str));        /* Length */

应该为：
  ((my_tty->driver)->write) (my_tty,        /* The tty itself */
                                           str,        /* String                 */
                                           strlen(str));        /* Length */

这个write函数只有三个函数。