AUSAM/source/S/col.c

/*
**	Col
*/


# define PL 102
# define ESC 033
# define SI 017
# define SO 016
# define LINELN 800
char *page[PL];
char lbuff [LINELN], *line;


main ()
{
	int c, i, j, ll, cp, mustwr;
	extern int fin, fout;

	fin = dup(0);
	fout = dup(1);

	for (ll=0; ll<PL; ll++)
		page[ll] = 0;

	c = 1;
	cp = ll = 0;
	line = lbuff;
	mustwr = PL;
	
	while (c>0)
		switch (c = getchar())
		{
		case '\n':
			store (ll%PL);
			if (++ll >= mustwr)
				if (page[ll%PL] != 0)
				{
					printf ("%s\n",page[ll%PL]);
					mustwr++;
					free (page[ll%PL]);
					page[ll%PL]=0;
				}
			fetch (ll%PL);
			cp = 0;
			continue;

		case '\0': continue;

		case ESC:
			c = getchar();
			if (c == '7')
			{
				store(ll%PL);
				ll--;
				fetch (ll%PL);
			}
			else
			{
				outc (ESC, &line);
				outc (c, &line );
			}
			continue;

		case '\r':
			line = lbuff;
			continue;

		case '\t':
			outc (' ', &line);
			cp = line-lbuff;
			while (cp++%8)
				outc(' ', &line);
			continue;

		default:
			outc(c, &line);
		}


	for (i=0; i<PL; i++)
		if (page[(mustwr+i)%PL] != 0)
			printf ("%s\n",page[(mustwr+i) % PL]);
	flush();
}


outc (c, lp)
char **lp;
{
	int	j = 0;

	while (j >0 || *(*lp) == '\b' || *(*lp) == ESC || **lp == SI || **lp == SO)
	{
		switch (*(*lp))
		{
		case '\b':
			j++;
			(*lp)++;
			break;

		case '\0':
			*(*lp)++ = ' ';
			j--;
			break;

		case ESC: /* 'escape' */
			(*lp) =+ 2;
			break;

		case SI:
		case SO:
			(*lp)++;
			break;

		default:
			(*lp)++;
			j--;
			break;
		}
	}
	
	if (c != ' ' || *(*lp) == '\0')
		*(*lp) = c;
	(*lp)++;
}


store (ll)
{
	if (page[ll] != 0)
		free (page[ll]);
	page[ll] = alloc ( leng (lbuff) + 2);
	copy (page[ll],lbuff);
}


fetch(ll)
{
	int i;

	for (i=0; i < LINELN; i++)
		lbuff[i] = '\0';
	copy (line=lbuff, page[ll]);
}


copy (s,t)
char *s, *t;
{
	if (t == 0)
		return (*s=0);
	while (*s++ = *t++);
}


leng (s)
char *s;
{
	int l;

	for (l=0; s[l]; l++);
	return (l);
}