chparse.c   [plain text]

/* $XFree86: xc/programs/xtrap/chparse.c,v 1.4 2003/05/27 22:27:13 tsi Exp $ */
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Permission to use, copy, modify, and distribute this software and its 
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ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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*****************************************************************************/
/*
**++
**  FACILITY:  chparse - ASCII ESC & CSI parser
**
**  MODULE DESCRIPTION:
**
**      This module accepts single character I/O from
**      stdin and returns a parsed character or sequence
**      of characters.  This is to be used in conjunction
**      with passing data from dragon-speak to XTrap.
**
**  AUTHORS:
**
**      Roy Lomicka (revised by Martin Minow & later Kenneth B. Miller)
**
**  CREATION DATE:  March 26, 1991
**
**  DESIGN ISSUES:
**
**      The algorithm is rather obscure.  However, it was decided
**      that it should be left in its original condition since it
**      closely depicts the state transition diagram for ASCII
**      sequences (about the only good thing goto's are for;) .
**      The old-fashioned bracketing and tabbing schemed were
**      also preserved for posterity.
**
**--
*/

#include	<stdio.h>
#include	<ctype.h>
#ifdef vms
#include	<ssdef.h>
#include	<stsdef.h>
#include	<iodef.h>
#include	<descrip.h>
#else
#include	<sys/types.h>
#include	<sys/time.h>
#endif
#include	<string.h>
#include	<unistd.h>
#include	"chparse.h"

#ifdef __QNX__
#include <sys/select.h>
#endif

#ifndef	VERBOSE
#define	VERBOSE	0
#endif

#ifndef FALSE
#define	FALSE	0
#define	TRUE	1
#endif
#define	EOS	'\0'
#define	ERROR	(-1)
#define	TIMEOUT	(-2)
#define	NPARAM	8
#define	NINTER	8
#define	BUFFLEN	10			/* Size of typeahead buffer	*/
#ifndef	EXIT_SUCCESS
#ifdef vms
#define	EXIT_SUCCESS	(SS$_NORMAL | STS$M_INHIB_MSG)
#define	EXIT_FAILURE	(SS$_ABORT)
#else
#define EXIT_SUCCESS	0
#define EXIT_FAILURE	1
#endif
#endif

#define	NUL	0x00
#define	CAN	0x18
#define	SUB	0x1A
#define	ESC	0x1B
#define DEL	0x7F
#define SS3     0x8f
#define	DCS	0x90
#define	CSI	0x9B
#define	ST	0x9C
#define	OSC	0x9D
#define	PM	0x9E
#define	APC	0x9F

static int kbinr(int max_delay);

/*
 * Escape sequence parser, obscure but useful.
 */
int chparse(
int		max_delay,
int		rest_delay,
int		*state,		/* Parser state (n.z. if incomplete)	*/
int		*private,	/* Sequence private char, 'X' if error	*/
int		param[],	/* numeric param, starting at param[1]	*/
int		*nparam,	/* Number of parameters			*/
int		inter[],	/* intermediate char, starting at [1]	*/
int		*ninter,	/* Number of intermediates		*/
int		*final)		/* Sequence terminator			*/
{
	register int		c;
	register int		i;

	if (*state == 0)
	    *private = 0;
label1:	c = kbinr(max_delay);
#if 0
	printf("c %02x, *state %02x, *nparam %d\n", c, *state, *nparam);
#endif
	max_delay = rest_delay;
label2:	switch (c) {
	case NUL:
	case DEL:
	    goto label5;
	case ESC:
	case CSI:
        case SS3:
	case DCS:
	case OSC:
	case PM:
	case APC:
	    *state = c;
	    *private = 0;
	    for (i = 0; i < NPARAM; i++)
		param[i] = 0;
	    for (i = 0; i < NINTER; i++)
		inter[i] = EOS;
	    *nparam = *ninter = 0;
	    goto label1;
	}
	if (*state == 0)
	    goto label5;
	if ((c >= 0x80 && c < 0xA0)
	 || c == TIMEOUT
	 || c == ERROR
	 || c == CAN
	 || c == SUB) {
	    *state = 0;
	    goto label5;
	}
	if (c < 0x20)				/* Doesn't stop seq.	*/
	    goto label5;
	if (c <= 0x2F) {
	    if (*ninter < 7)
		inter[++*ninter] = c;
	    goto label1;
	}
	if (*state == ESC) {
	    if (*ninter == 0
	     && (c & 0x3F) < 0x20) {
		c = (c & 0x3F) + 0x80;
		goto label2;
	    }
	    goto label4;
	}
	if (c >= 0x40)
	    goto label3;
	else if (c >= 0x3C) {			/* Private introducer	*/
	    if (*nparam != 0)
		 *private = 'X';
	    else {
		*private = c;
		*nparam = 1;
	    }
	    goto label1;
	}
	if (*nparam == 0)
	    *nparam = 1;
	if (*ninter != 0) {
	    *ninter = 0;
	    *private = 'X';
	}
	if (c == ';') {
	    if (*nparam >= (NPARAM - 1))
		*private = 'X';
	    else {
		++*nparam;
	    }
	    goto label1;
	}
	if (c > '9') {
	    *private = 'X';
	    goto label1;
	}
	param[*nparam] = (param[*nparam] * 10) + (c - '0');
	goto label1;
label3:	if (*nparam == 0)
	    *nparam = 1;
label4:	*final = c;
	c = *state;
	*state = 0;
label5:	return (c);
}

void dumpsequence(
int            state,
int		c,
int		private,	/* Sequence private char, 'X' if error	*/
int		param[],	/* numeric param, starting at param[1]	*/
int		nparam,		/* Number of parameters			*/
int		inter[],	/* intermediate char, starting at [1]	*/
int		ninter,		/* Number of intermediates		*/
int		final,		/* Sequence terminator			*/
short           *column)        /* column display count                 */
{
    register int	i;

    if (isascii(c) && isprint(c)) {
        *column +=2;
        if (*column >= 79) {
            printf("\n");
            *column = 2;
        }
        printf("%c ", c);
    }
    else if (private == 'X') {
        *column += strlen("bad sequence ");
        if (*column >= 79) {
            printf("\n");
            *column = strlen("bad sequence ");
        }
        printf("bad sequence ");
    }
    else if (state != NUL) {
        *column += 32;
        if (*column >= 79) {
            printf("\n");
            *column = 32;
        }
        printf("incomplete sequence (type <%02x>) ", state);
    }
    else {
        *column += 5;    /* update total chars printed */ 
        if (*column >= 79) {
            printf("\n");
            *column = 6;
        }
        switch (c) {
        case ESC:	printf("<ESC>");	break;
        case DCS:	printf("<DCS>");	break;
        case CSI:	printf("<CSI>");	break;
        case SS3:	printf("<SS3>");	break;
        default:	printf("<%02x>", c & 0xFF);
        }
        if (c == ESC || c == DCS || c == CSI || c == SS3) {
            *column += 1 + nparam*2 + ninter + 1;    /* total chars printed */ 
            if (*column >= 79) {
                printf("\n");
                *column = 1 + nparam*2 + ninter + 1;
            }
    	    if (private != NUL && private != 'X')
    	        printf("%c", private);
            for (i = 1; i <= nparam; i++)
    	        printf("%s%d", (i > 1) ? "," : " ", param[i]);
	    for (i = 1; i <= ninter; i++)
	        printf("%c", inter[i]);
	    printf("%c", final);
        }
        (*column)++;
        if (*column >= 79) {
            printf("\n");
            *column = 1;
        }
        printf(" ");
    }
}

#ifdef vms
/*
 * Read a character from the terminal (with selectable timeout)
 */

int
kbinr(timeout)
int		timeout;		/* In seconds, 0 == immediately	*/
/*
 * Get one byte without echoing, if available.  Returns
 *	ERROR		Something is dwrong
 *	TIMEOUT		Nothing read within limit.
 * Note:
 *	timeout = 0	return immediately if nothing is present
 *	timeout = 1	Indeterminate, do not use
 *	timeout = 2	Wait at least one second.
 */
{
	register int	incount;
	static char	buffer[BUFFLEN];
	static char	*bufptr = buffer;
	static char	*bufend = buffer;

	if (bufptr >= bufend) {
	    bufptr = bufend = buffer;
	    incount = vmsread(buffer, BUFFLEN, 0);
	    if (incount == TIMEOUT)
		incount = vmsread(buffer, 1, timeout);
	    if (incount <= 0)
		return (incount);
	    bufend = &buffer[incount];
	}
	return (*bufptr++ & 0xFF);
}

static int		tt_channel;	/* Gets channel number		*/
typedef	struct {
    short int	status;
    short int	term_offset;
    short int	terminator;
    short int	term_size;
} IOSTAB;

int
vmsread(buffer, size, timeout)
char		*buffer;
int		size;
int		timeout;
{
	register int		status;
	IOSTAB			iostab;
	static $DESCRIPTOR(tt_device, "SYS$COMMAND");
	static long	termset[2] = { 0, 0 };	/* No terminator	*/
	static short	opened = FALSE;		/* TRUE when opened	*/

	if (!opened) {
	    status = sys$assign(&tt_device, &tt_channel, 0, 0);
	    if (status != SS$_NORMAL)
		lib$stop(status);
            opened = TRUE;
	}
	status = sys$qiow(
		0,			/* Event flag 			*/
		tt_channel,		/* Input channel		*/
		IO$_READLBLK | IO$M_NOECHO | IO$M_NOFILTR | IO$M_TIMED,
					/* Read, no echo, no translate	*/
		&iostab,		/* I/O status block		*/
		NULL,			/* AST block (none)		*/
		0,			/* AST parameter		*/
		buffer,			/* P1 - input buffer		*/
		size,			/* P2 - buffer length		*/
		timeout,		/* P3 - timeout			*/
		&termset,		/* P4 - terminator set		*/
		NULL,			/* P5 - ignored (prompt buffer)	*/
		0			/* P6 - ignored (prompt size)	*/
	);
	if (status == SS$_TIMEOUT)
	    return (TIMEOUT);
	else if (status != SS$_NORMAL)
	    return (ERROR);
	else {
	    if ((status = iostab.term_offset + iostab.term_size) > 0)
		return (status);
	    return (TIMEOUT);
	}
}
#else
static int
kbinr(int max_delay)
{
	auto int		fdmask;
	struct timeval		timeout;
	int			count;
	static unsigned char	buffer[80];
	static unsigned char	*bend;
	static unsigned char	*bptr;

	if (bptr >= bend) {
	    fdmask = 1 << fileno(stdin);
	    timeout.tv_usec = 0;
	    timeout.tv_sec = max_delay;
	    count = select(fileno(stdin) + 1, (fd_set *)&fdmask, NULL, NULL, &timeout);
	    if (count < 0)
		return (ERROR);
	    else if (count == 0)
		return (TIMEOUT);
	    if (count >= sizeof buffer)
		count = sizeof buffer;
	    count = read(fileno(stdin), buffer, count);
	    if (count <= 0)
		return (ERROR);
	    bptr = buffer;
	    bend = buffer + count;
	}
	return (*bptr++);
}
#endif