#! /usr/bin/awk -f

# BEGIN {
#	 f = fopen("preproc.c");
#	 while((c = fgetc(f)) != -1)
#	 	 printf("%c", c);
#	 fclose(f);
#	 exit(0);
# }

function fopen(filename)
{
	_FOPEN[filename] = 1;
	return (filename);
}

function fclose(filename)
{
	if(_FOPEN[filename]) {
		delete _FOPEN[filename];
		delete _FGETC;
		close(filename);
	}
	return;
}

function fgetc(filename ,lastline)
{
	if(! _FOPEN[filename])
		return (-1);
	_FGETC[1] = ((_FGETC[1] > 0) ? _FGETC[1] : 1);
	if((_FGETC[1] >= _FGETC[0]) || ((!_FGETC[2]))) {
		if((getline lastline < filename) > 0) {
			_FGETC[2] = (lastline "\n");
			_FGETC[0] = (length(_FGETC[2]) + 1);
			_FGETC[1] = 1;
		} else
			return (-1);
	}
	return (substr(_FGETC[2], (_FGETC[1]++), 1));
}

function ungetc(char)
{
	return (ungets(substr(char, 1, 1)));
}

function fgetline(filename, c,l)
{
	if((c = fgetc(filename)) == -1)
		return (-1);
	if(c == "\n")
		return ("");
	l = (l c);
	while(((c = fgetc(filename)) != -1) && (c != "\n"))
		l = (l c);
	return (l);
}

function ungets(string ,result)
{
    	result = (substr(_FGETC[2], 1, (_FGETC[1] - 1)) (string) \
			substr(_FGETC[2], _FGETC[1], (_FGETC[0] - _FGETC[1])));
	_FGETC[2] = (result);
	_FGETC[0] += (length(string) + ((_FGETC[1] > 0) ? 0 : 1));
	return (result);
}