#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/io.h>
#include <string.h>
int errormsg(int);
int main(int argc, char *argv[])
{
   unsigned int base,k,bit,i,b;
   unsigned char val,byte,maskset,maskclr;
   int bs,ro;
   bs=0;
   base=0;
   maskset=0;
   maskclr=0;
   byte=0;
   val=0;
   k=0;
   bit=0;
   ro=0;
   //read command line parameters
   if(argc < 2) errormsg(0);
   for(i=1; i<argc; i++)
   {
      k=0;
      if(strcmp("-base",argv[i])==0) k=1;
      if(strcmp("-set",argv[i])==0) k=2;
      if(strcmp("-clr",argv[i])==0) k=3;
      if(strcmp("-read",argv[i])==0) k=4;
      if(strcmp("-help",argv[i])==0) k=5;
      switch(k)
      {
		 case 1:
		    // -base
		    i++;
		    if((argv[i][0] == '0')&&((argv[i][1]=='x')||(argv[i][1]=='X')))
		    {
			   sscanf(&argv[i][2],"%x",&base);
			}
			else
			{
		       base = atoi(argv[i]);
		    }
		    break;
		 case 2:
		    // -set
		    i++;
		    if((strlen(argv[i]) > 1)||(i>=argc)||(argv[i][0]<'0')||(argv[i][0]>'7')) errormsg(2);
		    bit = atoi(argv[i]);
		    maskset = maskset | ( 1 << bit);
		    break;
		 case 3:
		    // -clr
		    i++;
		    if((strlen(argv[i]) > 1)||(i>=argc)||(argv[i][0]<'0')||(argv[i][0]>'7')) errormsg(3);
		    bit = atoi(argv[i]);
		    maskclr = maskclr | ( 1 << bit);
		    break;
		 case 4:
		    // -read
		    ro=1;
	        break;
	     case 5:
	        // -help
	        printf("Usage: %s [options] [byte]\n", argv[0]);
	        printf("Options:\n");
	        printf("\t-base <addr>\t-specifie base addrres of LPT port decimal or hex, default 0x378.\n");
	        printf("\t-set <bit>\t-set specified bit number(0-7) to hi level. Can use to 8 options -set.\n");
	        printf("\t-clr <bit>\t-clear specified bit number(0-7) to low level. Can use to 8 options -clr.\n");
	        printf("\t-read   \t-read current value from LPT without ani change in LPT port.\n");
	        printf("\t-help   \t-show this message\n");
	        printf("byte \t- byte for send to LPT port. If specified -set or -clr option <byte> will be changed before send to LPT port\n");
	        exit(0);
	     break;	 
		 default:
		    // byte
		    if((argv[i][0] == '0')&&((argv[i][1]=='x')||(argv[i][1]=='X')))
		    {
			  sscanf(&argv[i][2],"%x",&b);
			  byte=b;
			}
			else
			{
		       byte = atoi(argv[i]);
		    }
		    bs=1;
		    break;
	  }
   }
   
   if(base == 0) base = 0x378;  // default base address LPT
   maskclr = maskclr ^ 0xff;
   
   if(ioperm(base, 3, 1))errormsg(1); // check permission
   val = inb(base); // read from port
   if(ro == 1)
   {
      printf("0x%02x\n",val);
      exit(0);
   }
   if(bs == 0) byte = val;
   byte = byte | maskset;
   byte = byte & maskclr;
   printf("0x%02x\n",byte);
   outb(byte,base); // write to port
   exit(0);
}

int errormsg(int msgn)
{
	char msg[10][80]={
	"Lost argument(s), use -help for help",
	"Couldn't get this port. You must be root or specify correct port address",
	"After option -set must be specified bit number, valid range 0-7",
	"After option -clr must be specified bit number, valid range 0-7"
	};
	printf("ERROR: %s\n",msg[msgn]);
    exit(-1);
}