/*  koi2alt
    Convert a file in ALT coding to KOI-8.
    Written by Leonid Zeitlin, tseitlin@gandalf.umcs.maine.edu.
    This program is free software. Permission is hereby granted to use,
    copy, modify and redistribute this program for any purpose without fee.
    This program is provided on "as is" basis with absolutely no warranty!
    Author belives that this program can be compiled and run on any system
    that has a C compiler, but by no means does he garantee its portability
    to any particular system.
    
    To compile on UNIX:
      gcc -o koi2alt koi2alt.c

    To compile on MS DOS use Turbo C

    Usage: koi2alt [-|+cr] infile outfile
           Infile in KOI must exist. Outfile in ALT will be created
	   Options: -cr - remove carrige returns at the ends of lines
                    +cr - add carrige returns at the ends of lines.	   
*/

#include<stdio.h>
#include<stdlib.h>

void usage()
{
  printf("Usage:\n");
  printf("koi2alt [-|+cr] infile outfile\n");
  printf("  converts infile in KOI-8 coding to outfile in ALT coding\n");
  printf("  Options: -cr - remove carrige returns at the ends of lines\n");
  printf("           +cr - add carrige returns at the ends of lines.\n"); 
}

int main(int argc, char *argv[])
{
  int alt[64]=
  {160, 161, 162, 163, 164, 165, 166, 167, 168, 169, 170, 171, 172, 173, 174,
   175, 224, 225, 226, 227, 228, 229, 230, 231, 232, 233, 234, 235, 236, 237,
   238, 239, 128, 129, 130, 131, 132, 133, 134, 135, 136, 137, 138, 139, 140,
   141, 142, 143, 144, 145, 146, 147, 148, 149, 150, 151, 152, 153, 154, 155,
   156, 157, 158, 159};
  int koi[64]=
  {193, 194, 215, 199, 196, 197, 214, 218, 201, 202, 203, 204, 205, 206, 207,
   208, 210, 211, 212, 213, 198, 200, 195, 222, 219, 221, 223, 217, 216, 220,
   192, 209, 225, 226, 247, 231, 228, 229, 246, 250, 233, 234, 235, 236, 237,
   238, 239, 240, 242, 243, 244, 245, 230, 232, 227, 254, 251, 253, 255, 249,
   248, 252, 224, 241};
  int buf;
  int i=1, cr=0;
  FILE *fp, *fq;
  
  if (argc!=3 && argc!=4)
  {
    usage();
    exit(1);
  }
  if (argc==4)
  {
    i=2;
    if (strcmp(argv[1], "-cr")==0) cr=-1;
    else if (strcmp(argv[1], "+cr")==0) cr=1;
    else
    {
      usage();
      exit(1);
    }
  }
  
  if ((fp=fopen(argv[i], "rb"))==NULL)
  {
    fprintf(stderr, "Cannot open file %s for reading!\n", argv[i]);
    exit(2);
  }
  if ((fq=fopen(argv[i+1], "wb"))==NULL)
  {
    fprintf(stderr, "Cannot open file %s for writing!\n", argv[i+1]);
    exit(3);
  }
  while ((buf=fgetc(fp))!=EOF)
  {
    if (cr==-1 && buf=='\r') continue;
    if (cr==1 && buf=='\n') fputc('\r', fq);
    if (buf>127)
    {
      for (i=0; (buf!=koi[i]) && (i<64); ++i);
      if (i<64) fputc(alt[i], fq);
      else fputc(buf, fq);
    }
    else fputc(buf, fq);

  }
  return 0;
}