/*
	Copyright (C) 1991, Marcus J. Ranum. All rights reserved.
*/

#ifndef	lint
static	char	RCSid[] = "$Header: /usr/users/mjr/hacks/umud/DB/RCS/comp.c,v 1.1 91/07/04 17:33:08 mjr Rel $";
#endif

#include	"config.h"
#include	<stdio.h>

#include	"comp.h"

static	char	ctab[128][128];

void
comp_init()
{
	int i;
	int j;

	for(i = 0; i < 128; i++)
		for(j = 0; j < 128; j++)
			ctab[i][j] = 0;

	for(i = 0; i < 128; i++)
		ctab[ctok[i][0]][ctok[i][1]] = i | 0x80;
}




compress(fin,fout)
FILE	*fin;
FILE	*fout;
{
	char	c;
	char	nxt = -1;

	while(1) {
		if(nxt == -1)
			c = getc(fin);
		else
			c = nxt;

		nxt = getc(fin);
		if(ferror(fin) || feof(fin)) {
			if(c != -1)
				putc(c,fout);
			return(ferror(fin) == 0);
		}

		if(ctab[c][nxt]) {
			if(fputc(ctab[c][nxt],fout) == EOF)
				return(1);
			nxt = -1;
		} else {
			if(fputc(c,fout) == EOF)
				return(1);
		}

	}
}



decompress(fin,fout)
FILE	*fin;
FILE	*fout;
{
	char	c;

	while(1) {
		c = getc(fin);
		if(feof(fin) || ferror(fin))
			return(ferror(fin) == 0);

		if(c & 0x80) {
			putc(ctok[c & 0x7f][0],fout);
			putc(ctok[c & 0x7f][1],fout);
		} else
			putc(c,fout);
	}
}



main(ac,av)
int	ac;
char	*av[];
{
	char	*p;
	extern	char	*rindex();

	comp_init();
	if(ac < 2)
		exit(compress(stdin,stdout));
	else
		exit(decompress(stdin,stdout));
}