/*
Title   : CBM2IBM.C
LastEdit: 02/05/89
Author  : Kim Moser
System  : Turbo-C 2.0, MS DOS
Descrip : Filter which copies stdin to stdout, converting CBM "PETASCII"
	  to IBM PC [MS DOS] format, or vice versa, depending on command
	  line switch used.

Notes   : If using Turbo-C, compile in the "Small" memory model.

Usage:
	CBM2IBM  -c | -i

	Options:
		-c = stdin assumed to be in CBM format (CR becomes CR/LF)
		-i = stdin assumed to be in IBM format (CR/LF becomes CR)
*/

#include <stdio.h>
#include <stdlib.h>  /* exit() */
#include <ctype.h>  /* toupper() */
#include <io.h>  /* setmode() */
#include <fcntl.h>  /* O_BINARY */

#define CR      13
#define LF      10

void usage(void)
/* Shows CBM2IBM usage and credits */
{
        printf( "CBM2IBM  v1.0  (C) 1988  Kim Moser  All Rights Reserved\n" );
        printf( "  Converts text files between CBM and IBM format\n\n" );

        printf( "  Usage:\n" );
        printf( "     CBM2IBM  -c | -i\n\n" );

        printf( "  Options:\n" );
        printf( "      -c = stdin assumed to be in CBM format (CR becomes CR/LF)\n" );
        printf( "      -i = stdin assumed to be in IBM format (CR/LF becomes CR)\n" );
}

void main(argc,argv)
int argc;
char *argv[];
{
        register int ch;  /* Must be signed so that EOF (probably -1) can be represented */

	switch ( toupper(argv[1][1]) ) {  /* Should be '-i' or '-c' */
                case 'I':
                        /* IBM -> CBM */
                        while ( (ch=getchar()) != EOF ) {
				if ( ch == '\n' )
					/* CBM expects just CR for new line */
					ch = CR;
                                else if ( (ch>64) && (ch<91) )
                                        ch += 128;
                                else if ( (ch>96) && (ch<123) )
                                        ch -= 32;

				putchar(ch);
                        }
                        break;
                case 'C':
                        /* CBM -> IBM */
		        setmode( fileno(stdin), O_BINARY );
			  /* So that input stream is not prefiltered */

                        while ( (ch=getchar()) != EOF ) {
                                if ( (ch>64) && (ch<91) )
                                        ch += 32;
                                else if ( (ch>192) && (ch<219) )
                                        ch -= 128;

                                if (ch != LF) {  /* Ignore lone linefeeds */
                                        if (ch == CR)  /* CR -> CR/LF */
                                                ch = '\n';
                                        putchar(ch);
                                }
                        }
                        break;
                default:  /* Missing or invalid command line param(s) */
			usage();
			if (argc == 2)
				printf( "\nInvalid command line switch: '%s'\n", argv[1] );
                        exit(1);
        }
}