/************************************************************************/
/*									*/
/*	File:	pp3.c							*/
/*									*/
/*	General I/O for PP.						*/
/*									*/
/*	Written by:							*/
/*			Gary Oliver					*/
/*			3420 NW Elmwood Dr.				*/
/*			PO Box 826					*/
/*			Corvallis, Oregon 97339				*/
/*			(503)758-5549					*/
/*	Maintained by:							*/
/*			Kirk Bailey					*/
/*			Logical Systems					*/
/*			P.O. Box 1702					*/
/*			Corvallis, OR 97339				*/
/*			(503)753-9051					*/
/*									*/
/*	This program is hereby placed in the public domain.  In		*/
/*	contrast to other claims of "public domain", this means no	*/
/*	copyright is claimed and you may do anything you like with PP,	*/
/*	including selling it!  As a gesture of courtesy, please retain	*/
/*	the authorship information in the source code and		*/
/*	documentation.							*/
/*									*/
/*	Functions contained in this module:				*/
/*									*/
/*		cur_user	Select current disk-user (CPM).		*/
/*		do_line		Issue #line output directive.		*/
/*		doinclude	Process #include directive.		*/
/*		doline		Process #line directive.		*/
/*		gchbuf		Get char from file buffer.		*/
/*		gchfile		Get new buffer from file and return ch.	*/
/*		gchpb		Get char from pushback buffers.		*/
/*		getchn		Get char from buffer, ignoring "\\n"	*/
/*		inc_open	Open file for inclusion.		*/
/*		init_path	Initialize Ipath information.		*/
/*		popfile		Pop to next lower file level.		*/
/*		readline	Read and macro-process a line of text.	*/
/*		scaneol		Scan to eol, leaving EOL as next token.	*/
/*		set_user	Select a disk-user (CPM).		*/
/*		trigraph	Handle ANSI trigraph translations.	*/
/*									*/
/************************************************************************/

#include 	"pp.h"
#include	"ppext.h"

#if	HOST == H_CPM
/************************************************************************/
/*									*/
/*	cur_user							*/
/*									*/
/*	Restore disk/user to that at program start.			*/
/*									*/
/************************************************************************/

void
cur_user()
	{
	bdos(BDOS_SELDISK,Orig_disk);
	bdos(BDOS_USER,Orig_user);
	}
#endif	/* HOST == H_CPM */

/************************************************************************/
/*									*/
/*	do_line								*/
/*									*/
/*	Write #line directive to output file, synching to current	*/
/*	input line number and file name.				*/
/*									*/
/************************************************************************/

/*
 *	The following definition of NL_CHAR is used to minimize the file
 *	storage space required for the output file PP writes.  If the external
 *	file format stores "\n" as a single character (as on the UNIX systems),
 *	then NL_CHAR is set to 1.  Otherwise it is set to 2 to reflect the CR/
 *	LF used for external files.  NLCHAR is only used by this function to
 *	optimize the tradeoff between emitting extra "#line" directives (if
 *	enabled), or to output extra "\n" characters instead.
 */
#if	(HOST == H_BSD)OR(HOST == H_MPW)OR(HOST == H_UNIX)OR(HOST == H_XENIX)
#define	NL_CHAR	1
#else	/* H_BSD || H_MPW || H_UNIX || H_XENIX */
#define	NL_CHAR	2
#endif	/* H_BSD || H_MPW || H_UNIX || H_XENIX */

void
do_line(at_bol)
	char			at_bol;	/* TRUE if already at BOL */
	{
	char			buf[TOKENSIZE + 1];
	char			filen[FILENAMESIZE + 1];
	register	int	n;

	n = Tokenline - Outline;	/* Difference in line #s */

	sprintf(filen," \"%s\"",Filestack[Tokenfile]->f_name);
	sprintf(buf,"%s#%s %d%s\n",
		!at_bol ? "\n" : "",	/* Emit a \n if needed */
			Lineopt == LINE_EXP ? "line" : "",
#if	TARGET == T_QC
				Tokenline-1,	/* QC bug */
#else	/* TARGET != T_QC */
				Tokenline,
#endif	/* TARGET == T_QC */
					Do_name ? filen : "");

#if	(TARGET == T_QC) OR (TARGET == T_QCX)
	if((!Do_name && (n >= 0) && (((unsigned int) n) <
		(strlen(buf)/NL_CHAR + 1))) || Do_asm)
#else	/* ! ((TARGET == T_QC) OR (TARGET == T_QCX)) */
	if(!Do_name && (n >= 0) && (((unsigned int) n) <
		(strlen(buf)/NL_CHAR + 1)))
#endif	/* (TARGET == T_QC) OR (TARGET == T_QCX) */
		{
		while(n-- > 0)
			putc('\n',Output);	/* Write newlines to synch */
		}
	else
		{
		fprintf(Output,buf);
		}

	Outline = Tokenline;		/* Make them the same */
	Do_name = FALSE;
	}

/************************************************************************/
/*									*/
/*	doinclude							*/
/*									*/
/*	Process #include file commands.					*/
/*									*/
/*	The file name is parsed and the file is opened.  A stack of	*/
/*	current files and file names is pushed, with the new one	*/
/*	being placed upon the top of the other, currently opened,	*/
/*	files.  Upon return, the next character read is from the	*/
/*	newly opened file.						*/
/*									*/
/*									*/
/************************************************************************/

void
doinclude()
	{
	char			buf[TOKENSIZE];
	register int		c;
	register int		d;
	register char		*incf;
	char			incfile[FILENAMESIZE + 1];
#if	HOST != H_CPM
	char			filename[FILENAMESIZE + 1];
	register char		**ip;
#endif	/* HOST != H_CPM */
	register int		ok;
#if	HOST == H_CPM
	register int		disk;
	register char		*p;
	register char		**ip;
	register int		user;
#endif	/* HOST == H_CPM */

#if	DEBUG
	if(Debug) printf("doinclude: include level:%d\n",Filelevel);
#endif	/* DEBUG */
	if(Filelevel >= FILESTACKSIZE)
		{
		non_fatal("Include file stack overflow","");
		return;
		}
/*
 *	Read line and process any macros encountered.
 */
	pbcstr(readline(buf,TOKENSIZE,GT_ANGLE));

	while(istype((c = getchn()),C_W))
		;

	if(c == EOF)
		end_of_file();
	else if(c == '<')
		d = '>';
	else if(c == '"')
		d = '"';
	else
		{
		non_fatal("Bad include argument","");
		if(c == '\n')
			pushback('\n');
		return;
		}

	for(incf = incfile; c != EOF && c != '\n';)
		{
		if((c = getchn()) == d)
			break;

		if(incf >= &incfile[FILENAMESIZE])
			{
			non_fatal("Include file name too long","");
			return;
			}
		else
			*incf++ = c;
		}

	while((c != '\n') && (c != EOF))
		c = getchn();		/* Slurp trailing \n */

	if(incf != incfile)
		*incf = '\0';
	else
		{
		non_fatal("Illegal file name","");
		return;
		}

	if(Lineopt)
		do_line(TRUE);		/* Catch up before inc file switch */

#if	DEBUG
	if(Debug) printf("doinclude: <%s>\n",incfile);
#endif	/* DEBUG */

	if(Verbose)
		printf("*** Include %s\n",incfile);

	ok = FALSE;

#if	HOST == H_CPM		/* The following stuff works only under CP/M */

/*
 *	Determine the type of include: if d == '<' then search the path
 *	indicated by the -i parameter (or the default.)  If the delimiter is
 *	'"' then include the current directory as well.
 */
	if(d == '"')
		ok = inc_open(incfile,-1,0);	/* The current location */

	/* Try all path options in -i list (including DFLT_PATH stuff) */
	for(ip = &Ipath[0]; (*ip != NULL) && !ok; ip++)
		{
		p = *ip;

		while(istype(*p & 0xFF,C_W))
			++p;		/* Skip white space */

		disk = *p++;		/* Get drive letter */

		if(isupper(disk))
			disk = tolower(disk);

		if(disk == '*')
			user = -1;	/* Use the default */
		else if((disk >= 'a') && (disk <= 'p'))
			{
			disk -= 'a';	/* Drive */

			if(! isdigit(*p))
				user = -1;	/* Default */
			else
				{
				user = atoi(p);
				if((user < 0) || (user > 31))
					{
					non_fatal("Illegal user number","");
					return;
					}
				}
			}
		else
			{
			non_fatal("Illegal disk drive specifier","");
			return;
			}

		ok = inc_open(incfile,user,disk);
		}

#else	/* HOST != H_CPM */

	if(d == '"')
		{
		/* Look in current directory */
		strcpy(filename,Filestack[Filelevel]->f_name);
		if(strrchr(filename,SLASHCHAR))
			strcpy(strrchr(filename,SLASHCHAR) + 1,incfile);
		else
			strcpy(filename,incfile);

		ok = inc_open(filename);
		}

	/* Look through all paths for an existance of the file */

	for(ip = &Ipath[0]; *ip != NULL && !ok; ip++)
		{
		strcpy(filename,*ip);	/* Copy path name */
		strcat(filename,SLASHSTR);	/* Append / for directory */
		strcat(filename,incfile);	/* Append local file name */
		ok = inc_open(filename);	/* Attempt an open */
		}

#endif	/* (HOST != H_CPM) */

#if	HOST == H_CPM
	cur_user();			/* Restore current user/disk */
#endif	/* HOST == H_CPM */

	if(! ok)
		non_fatal("Unable to open include file: ",incfile);
	pushback('\n');

	/* Let token scanner see first things on line */
	Lastnl = TRUE;
	}

/************************************************************************/
/*									*/
/*	doline								*/
/*									*/
/*	Set current line number and file identifier to that specified.	*/
/*									*/
/************************************************************************/

void
doline()
	{
	char			buf[TOKENSIZE];
	int			c;
	int			l;
	char			*p;
/*
 *	Read line and process any macros encountered.
 */
	pbcstr(readline(buf,TOKENSIZE,GT_STR));

	while(istype((c = getchn()),C_W))
		;

	if(istype(c,C_D))
		{
		for(l = 0; istype(c,C_D); c = getchn())
			l = l * 10 + c - '0';

		LLine = l - 1;		/* Set line number */

		pushback(c);
		c = getnstoken(GT_STR);

		if((c != '\n') && (c != EOF))
			{
			if(c == '"')
				{
				p = strrchr(Token,'"');	/* Find ending " */

				/* Allow for first " */
				if(p-Token > FILENAMESIZE)
					p = &Token[FILENAMESIZE + 1];

				*p = '\0';	/* Terminate it */
				strcpy(Filestack[Filelevel]->f_name,Token + 1);
				/* Need filename on "output" #line */
				Do_name = TRUE;
				}
			else
				{
				pushback(c);
				c = '\0';
				}
			}
		}
	else
		{
		pushback(c);
		c = '\0';
		}

	if(c == '\0')
		non_fatal("\"#line\" argument error","");

	while((c != '\n') && (c != EOF))
		c = getnstoken(GT_STR);	/* Slurp trailing \n */
	pushback('\n');
	}

/************************************************************************/
/*									*/
/*	gchbuf								*/
/*									*/
/*	Get char from input buffer.  If out of chars in buffer, read	*/
/*	another buffer.							*/
/*									*/
/************************************************************************/

int
gchbuf()
	{
	register int		c;

	for(;;)
		{
		if(Lasteol)
			{
			Lasteol = FALSE;
			LLine++;
			}

		if(! istype(c = (Bufc-- ? *Bufp++ : gchfile()),C_C))
			break;		/* If no need to examine closely */

#ifdef	IGNORE_CR
		if(c == '\r')
			continue;
#endif	/* IGNORE_CR */

		if(c == '\n')
			Lasteol = TRUE;	/* Inc line number next time */
#ifdef	PP_SYSIO
#if	HOST == H_CPM
		else if(c == ENDFILE)
			{
			Bufc = 0;
			continue;	/* Try to get next file */
			}
#endif	/* HOST == H_CPM */
#endif	/* PP_SYSIO */
		break;
		}
	return(c);			/* And exit */
	}

/************************************************************************/
/*									*/
/*	gchfile								*/
/*									*/
/*	Get next buffer of chars from input file.  If end of file	*/
/*	found, pop file level and read from lower file.  If out of	*/
/*	files, return EOF.						*/
/*									*/
/************************************************************************/

int
gchfile()
	{
#ifdef	PP_SYSIO
	extern	int		read();
#endif	/* PP_SYSIO */

	register struct	file	*f;

	if(Filelevel < 0)
		{
		Bufc = 0;
		return (EOF);
		}
	else if((Filestack[Filelevel]->f_eof) && popfile())
		return (A_trigraph ? trigraph() : gchbuf());

	if(Filelevel < 0)
		{
		Bufc = 0;
		return (EOF);
		}
	f = Filestack[Filelevel];

#if	HOST == H_CPM
	set_user();
#endif	/* HOST == H_CPM */

	Bufp = f->f_buf;		/* Set buffer address */

#ifdef	PP_SYSIO
	if((Bufc = read(f->f_fd, Bufp, BUFFERSIZE)) == 0)
#else	/* !PP_SYSIO */
	if((Bufc = fread(Bufp, 1, BUFFERSIZE, f->f_file)) == 0)
#endif	/* PP_SYSIO */
		{
		f->f_eof = TRUE;
		return ('\n');		/* Fake '\n' before EOF */
		}
#if	HOST == H_CPM
	cur_user();
#endif	/* HOST == H_CPM */

	Bufc--;
	return(*Bufp++ & 0xFF);		/* Return the char */
	}

/************************************************************************/
/*									*/
/*	gchpb								*/
/*									*/
/*	Get character from push-back buffer.  If out of chars, return	*/
/*	next char routine to get chars from file.			*/
/*									*/
/************************************************************************/

int
gchpb()
	{
	register int		c;

	for(;;)
		{
		if(Pbbufp->pb_type == PB_CHAR)
			c = (Pbbufp--)->pb_val.pb_char;	/* Pop the char */
		else if(Pbbufp->pb_type == PB_STRING)
			{
			/* Get next char from string */
			if((c = *(Pbbufp->pb_val.pb_str++) & 0xFF) == '\0')
				{
/*
 *	End of the string.  Pop the stack to get the next pushback buffer
 *	which contains the starting address for the string.
 */
				Pbbufp--;
/* Free up the memory */	free(Pbbufp->pb_val.pb_str);
/* Get nxt real pushback buf */	Pbbufp--;
/* Try again to get input */	continue;
				}
			}
		else
			{
			/* Assume PB_TOS and pop to file input */
/* Next char source */	Nextch = A_trigraph ? trigraph : gchbuf;
			return (A_trigraph ? trigraph() : gchbuf());
			}
		return (c);
		}
	}

/************************************************************************/
/*									*/
/*	getchn								*/
/*									*/
/*	Get next char from nextch() routine, ignoring \ followed	*/
/*	by a newline character.						*/
/*									*/
/************************************************************************/

int
getchn()
	{
	int			c;
	int			c2;

	for(;;)
		{
		if((c = nextch()) == '\\')
			{
			c2 = nextch();
			if(c2 == '\n')
				continue;	/* Ignore char and get next */

			pushback(c2);	/* We'll get to this char later */
			}
		return (c);
		}
	}

/************************************************************************/
/*									*/
/*	inc_open							*/
/*									*/
/*	Open an include file for the selected path.			*/
/*									*/
/************************************************************************/

#if	HOST == H_CPM
int
inc_open(incfile,u,d)
	register char		*incfile;
	int			u;
	int			d;
#else	/* HOST != H_CPM */
int
inc_open(incfile)
	char			*incfile;
#endif	/* HOST == H_CPM */
	{
#ifdef	PP_SYSIO
	extern	int		open();
#endif	/* PP_SYSIO */

	register int		v;
	register struct	file	*f;
	register struct file	*fold;

#if	HOST == H_CPM

#if	DEBUG
	if(Debug)
		printf("inc_open: %s on %c%d\n",incfile,d+'A',u);
#endif	/* DEBUG */

	if(u >= 0)
		{
		bdos(BDOS_USER,u);
		bdos(BDOS_SELDISK,d);
		}

#else	/* HOST != H_CPM */

#if	DEBUG
	if(Debug)
		printf("inc_open: %s\n",incfile);
#endif	/* DEBUG */

#endif	/* HOST == H_CPM */

	f = Filestack[Filelevel+1] =
		(struct file *) malloc(sizeof(struct file));

	if(f == NULL)
		out_of_memory();

#ifdef	PP_SYSIO
	if((v = ((f->f_fd = open(incfile,0)) != -1)) != 0)
#else	/* !PP_SYSIO */
	if((v = (int)((f->f_file = fopen(incfile,"r")) != NULL)) != 0)
#endif	/* PP_SYSIO */
		{
		if(Filelevel >= 0)	/* Don't do if first time thru */
			{
#if	DEBUG
			if(Debug)
				{
	printf("inc_open pushing: Bufc=%d, Bufp=%p, Lasteol=%d, Line=%d\n",
					Bufc,Bufp,Lasteol,LLine);
				}
#endif	/* DEBUG */

			fold = Filestack[Filelevel];
			fold->f_bufp = Bufp;	/* Save current buf ptr */
			fold->f_bufc = Bufc;	/* Save current buffer count */
			fold->f_lasteol = Lasteol;	/* Save last char */
			fold->f_line = LLine;	/* Save current line # */
			}
		Filelevel++;
		strcpy(f->f_name,incfile);
		LLine		= 1;	/* Initial line number		*/
		Bufc		= 0;	/* No chars in buffer		*/
		f->f_eof	= 	/* Not at eof yet		*/
		Lasteol		= FALSE;/* Last char was not EOL	*/
#if	HOST == H_CPM
		f->f_disk = d;
		f->f_user = u;
#endif	/* HOST == H_CPM */
		}
	else
		free((char *)f);	/* Return the memory used */

#if	HOST == H_CPM
	if(u >= 0)
		cur_user();		/* Restore current user/disk */
#endif	/* HOST == H_CPM */

	if(v)
		{
		Do_name = TRUE;
		return (TRUE);
		}
	else
		return (FALSE);
	}

/************************************************************************/
/*									*/
/*	init_path							*/
/*									*/
/*	Initialize path searching information.  Try to open a file	*/
/*	defined as PATHFILE on A0:.  If available, read in the path	*/
/*	default information, otherwise use CPM_PATH as the default.	*/
/*									*/
/*	If initializing for non-CPM, initialize Ipath to whatever is	*/
/*	specified by the PPINC environment variable or DFLT_PATH if no	*/
/*	matching environment variable is found.				*/
/*									*/
/************************************************************************/

void
init_path()
	{
#if	HOST == H_CPM
	register int		inum;
	char			pb[TOKENSIZE];
	register FILE		*pf;

	bdos(BDOS_USER,0);
	bdos(BDOS_SELDISK,0);		/* Select A0 */

	if(pf = fopen(PATHFILE,"r"))
		{
		/* Found the file -- read lines and use as paths */
		for(inum = Ipcnt; inum < NIPATHS; inum++)
			{
			if(fgets(pb,TOKENSIZE,pf) != NULL)
				{
				if((Ipath[inum] = malloc((unsigned)
					(strlen(pb) + 1))) == NULL)
					{
					out_of_memory();
					}
				else
/* Copy the default path */		strcpy(Ipath[inum],pb);
				}
			else
				{
				if(inum == Ipcnt)
					{
					/* Didn't find any -- give error msg */
				warning("Bad format on include path file: ",
						PATHFILE);
/* Use default path */			Ipath[inum++] = DFLT_PATH;
					}
				break;
				}
			}

		Ipcnt = inum;		/* Keep counter correct	*/

		if(fclose(pf) == EOF)
			{
			non_fatal("Unable to close include path file: ",
				PATHFILE);
			}
		}
	else
		Ipath[Ipcnt++] = DFLT_PATH;	/* The default path list */

	cur_user();			/* Restore user/disk defaults */
#endif	/* HOST == H_CPM */

#if	HOST != H_CPM

	char			*cptr1;
	char			*cptr2;
	char			pb[TOKENSIZE];
/*
 *	See if there is an environment variable for the default search path.
 */
	if((cptr1 = getenv(ENV_PATH)) == NULL)
		cptr1 = strcpy(pb,DFLT_PATH);	/* Nope, use default path */
	else
		cptr1 = strcpy(pb,cptr1);

	for(; (*cptr1 != '\0') && (Ipcnt < NIPATHS); cptr1 = cptr2)
		{
		if((cptr2 = strchr(cptr1,PATHPUNC)) != NULL)
			*cptr2++ = '\0';
		else
			cptr2 = "\0";

		if((Ipath[Ipcnt] = malloc((unsigned) (strlen(cptr1) + 1))) ==
			NULL)
			{
			out_of_memory();
			}
		else
			strcpy(Ipath[Ipcnt++],cptr1);
		}
#endif	/* HOST != H_CPM */
	}

/************************************************************************/
/*									*/
/*	popfile								*/
/*									*/
/*	Pop file stack to previous file and return FALSE if no more.	*/
/*									*/
/************************************************************************/

int
popfile()
	{
#ifdef	PP_SYSIO
	extern	int		close();
#endif	/* PP_SYSIO */
	register struct	file	*f;

#if	HOST == H_CPM
	set_user();
#endif	/* HOST == H_CPM */

#ifdef	PP_SYSIO
	if(close((f = Filestack[Filelevel])->f_fd) == -1)
#else	/* !PP_SYSIO */
	if(fclose((f = Filestack[Filelevel])->f_file) == EOF)
#endif	/* PP_SYSIO */
		non_fatal("Unable to close input/include file: ",f->f_name);

	free((char *)f);		/* Free the entry */

#if	HOST == H_CPM
	cur_user();
#endif	/* HOST == H_CPM */

	if(Filelevel-- == 0)
		return (FALSE);		/* At bottom level, real EOF */

	f = Filestack[Filelevel];

	if(Verbose)
		printf("*** Resume  %s\n",f->f_name);

	Do_name = TRUE;			/* Next time do_line called, name it */
	Bufc = f->f_bufc;
	Bufp = f->f_bufp;
	Lasteol = f->f_lasteol;
	LLine = f->f_line;

#if	DEBUG
	if(Debug)
		printf("popfile: Bufc=%d, Bufp=%p, Lasteol=%d, Line=%d\n",
			Bufc, Bufp, Lasteol, LLine);
#endif	/* DEBUG */

	return (TRUE);			/* All is ok -- return success */
	}

/************************************************************************/
/*									*/
/*	readline							*/
/*									*/
/*	Read and edit a line into buffer with macro expansion.		*/
/*									*/
/************************************************************************/

char	*
readline(buf,bufsize,flags)
	register char		*buf;
	register int		bufsize;
	register int		flags;
	{
	static	char		rbo[] = "Read buffer overflow";

	register char		*bufp;
	struct	symtab		*sy;
	register int		t;

	for(bufp = buf; (t = gettoken(flags)) != '\n'; )
		{
		if(t == EOF)
			end_of_file();
		if((t == LETTER) && ((sy = lookup(Token,NULL)) != NULL) &&
			(sy->disable != TRUE))
			{
			bufp = docall(sy,bufp,&buf[bufsize - 1]);
			}
		else
			bufp = addstr(bufp,&buf[bufsize - 1],rbo,Token);
		}
	pushback('\n');
	*bufp = '\0';

	for(bufp = buf; istype(*bufp & 0xFF,C_W); ++bufp)
		;			/* Skip leading blanks */

	return(bufp);
	}

/************************************************************************/
/*									*/
/*	scaneol								*/
/*									*/
/*	Scan for end of current line.					*/
/*									*/
/************************************************************************/

void
scaneol()
	{
	register int		t;

	while((t = gettoken(GT_STR)) != '\n')
		{
		if(t == EOF)
			return;		/* Absorb chars */
		}
	pushback('\n');			/* So the newline is seen */
	}

#if	HOST == H_CPM
/************************************************************************/
/*									*/
/*	set_user							*/
/*									*/
/*	Set disk/user to that of current input file.			*/
/*									*/
/************************************************************************/

void
set_user()
	{
	/* Don't change if < 0 */
	if(Filestack[Filelevel]->f_user >= 0)
		{
		bdos(BDOS_SELDISK,Filestack[Filelevel]->f_disk);
		bdos(BDOS_USER,Filestack[Filelevel]->f_user);
		}
	}
#endif	/* HOST == H_CPM */

/************************************************************************/
/*									*/
/*	trigraph							*/
/*									*/
/*	Handles ANSI trigraph substitutions (alternate to "gchbuf").	*/
/*									*/
/************************************************************************/

int
trigraph()
	{
	int			c;
	int			q_count;

	if((c = gchbuf()) == '?')
		{
		if((c = gchbuf()) == '?')
			{
			q_count = 0;	/* Extra '?' encountered */
			for(;;)
				{
				switch((int) (c = gchbuf()))
					{
					case '=':
						c = '#';
						break;
					case '(':
						c = '[';
						break;
					case '/':
						c = '\\';
						break;
					case ')':
						c = ']';
						break;
					case '\'':
						c = '^';
						break;
					case '<':
						c = '{';
						break;
					case '!':
						c = '|';
						break;
					case '>':
						c = '}';
						break;
					case '-':
						c = '~';
						break;
					case '?':
						q_count++;
						continue;
					default:
						pushback(c);
						pushback('?');
						c = '?';
						break;
					}
/*
 *	Handle stuff like "????????????#" correctly.
 */
				if(q_count > 0)
					{
					pushback(c);
					while(q_count-- > 1)
						pushback('?');
					c = '?';
					}
				break;
				}
			}
		else
			{
			pushback(c);
			c = '?';
			}
		}
	return (c);
	}