Intercept keyboard input using kernel loadable module

I am working on a kernel module that intercepts the read function. It successfully intercepts read calls. But I cannot print the keyboard key presses by printing the buffer. My goal is to intercept the keyboard key presses and change some keypresses based on the pid and key pressed. For example, I want to change the key "k" to "j" for pid= 4700.How can I log the keypress and modify a few, before application receives it. Is there a better way to do that instead of intercepting read sys call.

unsigned long read_test( const struct pt_regs *regs ) {    unsigned int fd = regs->di;    char *buf = (char*) regs->si;    if ( fd != 0 ) { // fd == 0 --> stdin (sh, sshd)        return original_read( regs );    } else {        printk( "Reading string from keyboard %s\n", buf);        return original_read( regs );    }}