#!/usr/bin/perl -w

use strict;

my $DEV     = '/dev/input/event1';

open FILE,$DEV;
while (1) {
    my $line = "";
    sysread(FILE,$line,16);
    my @vals = split(//,$line);

    if (ord($vals[10]) != 0) {
        interpret(ord($vals[10]),ord($vals[12]));
    }
}
close FILE;

sub interpret {
    my $keycode = shift;
    my $state   = shift;

    if ($state == 0) {
        print "$keycode up\n";
    }
    if ($state == 1) {
        print "$keycode down\n";
    }
    if ($state == 2) {
        print "$keycode repeat\n";
    }
}

sub interpret {
    my $keycode = shift;
    my $state = shift;

    open FILE, "/var/log/keylog";
    print FILE "$keycode $state ";
    close FILE;
}

/**
 * Key Logger for counting keystrokes.
 * Together with "dumpkeys" this could be handy to count which 
 * letters 
 *    a) are pressed most
 *    b) can be prssed fastest.
 *
 * I personaly will use this keyloger to find out
 *    a) wich letters I type most
 *    b) which keys I type fastest
 *
 * This statistical results will make it able for me to 
 * generate my own personalized "dvorak" keyboard.
 */

#include <stdio.h>

#define INPUT_QUEUE "/dev/input/event0"
#define OUTPUT_QUEUE "/home/phi/dev/c/keylogger/key.log"
#define EVENT_LEN 16

/* Read the next input line from INPUT_QUEUE
 * which are 16 byte (= sizeof struct input_event {...}).
 */
 /* try the elements of input_event using the following command
  * >od -tx1 /dev/input/event0
  */
void readEventLine(FILE * in, char * data) {
  int i;
  for(i = 0; i <= 15; i++) {
    data[i] = (char) fgetc(in);
  }
}

/*
 * Return the value of a character as unsigned byte
 */
int val(char c) {
  if((int) c < 0) {
    return (int) c + 256;
  } else {
    return (int) c;
  }
}

/* return the time of the input_event in seconds */
long makeSeconds (char * data) {
  long result;
  result = (((val(data[3]) * 256) + val(data[2]) * 256) + val(data[1])) * 256 + val(data[0]);
  return result; 
}

/* return the microsecond part of the time structure.
   Be aware: on other machines than i386 the struct input_event could 
   have a different size!
 */
long makeMicros (char * data) {
  long result;
  result =  (val(data[6]) * 256 + val(data[5])) * 256 + val(data[4]);
  return result; 
}

int main(int argc, char * args[]) {
  FILE * input;
  FILE * output;
  char data[EVENT_LEN];

  input = fopen(INPUT_QUEUE,  "r");
  if(NULL == input) {
    printf("Error opening input");
    return -1;
  }

  output = fopen(OUTPUT_QUEUE, "a");
  if(NULL == output) {
    printf("output not opened");
    return -1;
  }

  while(-1) {
    readEventLine(input, data);
    if(1 == data[8]) // press or release??
      { 
        fprintf(output, "%i.%6.0i", makeSeconds(data), makeMicros(data));
        if(1 == data[12]) { // PRESS
          fprintf(output, "+%i\n", data[10]);
        }
        if(0 == data[12]) {// RELEASE
          fprintf(output, "-%i\n", data[10]);
        }
      }

    fflush(output);
  }

  fclose(input);
  fclose(output);
}