xmodmap/dist/handle.c

/*

Copyright 1988, 1998  The Open Group

Permission to use, copy, modify, distribute, and sell this software and its
documentation for any purpose is hereby granted without fee, provided that
the above copyright notice appear in all copies and that both that
copyright notice and this permission notice appear in supporting
documentation.

The above copyright notice and this permission notice shall be included
in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
IN NO EVENT SHALL THE OPEN GROUP BE LIABLE FOR ANY CLAIM, DAMAGES OR
OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

Except as contained in this notice, the name of The Open Group shall
not be used in advertising or otherwise to promote the sale, use or
other dealings in this Software without prior written authorization
from The Open Group.

*/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <X11/Xos.h>
#include <X11/Xlib.h>
#include <stdio.h>
#include <ctype.h>
#include "xmodmap.h"
#include "wq.h"
#include <stdlib.h>
#include <stdint.h>

#ifdef HAVE_STRNCASECMP
#include <strings.h>
#endif

static XModifierKeymap *map = NULL;


/*
 * The routines in this file manipulate a queue of intructions.  Instead of
 * executing each line as it is entered, we build up a list of actions to
 * take and execute them all at the end.  This allows us to find all errors
 * at once, and to preserve the context in which we are looking up keysyms.
 */

struct wq work_queue = {NULL, NULL};


/*
 * common utility routines
 */

/*
 * This is a combination of reallocf() and reallocarray().
 * If the realloc fails, it frees the old pointer so it doesn't leak.
 */
static void *
reallocfarray(void *old, size_t num, size_t size)
{
    static void *new;

    if (size > 0 && num > (SIZE_MAX / size)) /* overflow would happen */
        new = NULL;
    else
        new = realloc(old, num * size);

    if (new == NULL)
        free(old);

    return new;
}

static KeyCode *
KeysymToKeycodes(Display *dpy, KeySym keysym, int *pnum_kcs)
{
    KeyCode *kcs = NULL;
    int i, j;

    *pnum_kcs = 0;
    for (i = min_keycode; i <= max_keycode; i++) {
	for (j = 0; j < 8; j++) {
	    if (XKeycodeToKeysym(dpy, (KeyCode) i, j) == keysym) {
		if (!kcs)
		    kcs = malloc(sizeof(KeyCode));
		else
		    kcs = reallocfarray(kcs, (*pnum_kcs + 1), sizeof(KeyCode));
		if (!kcs) {
		    fprintf(stderr, "attempt to allocate %ld byte keycode set",
			    (long) ((*pnum_kcs + 1) * sizeof (KeyCode)));
		    return NULL;
		}
		kcs[*pnum_kcs] = i;
		*pnum_kcs += 1;
		break;
	    }
	}
    }
    return kcs;
}

static char *
copy_to_scratch(const char *s, int len)
{
    static char *buf = NULL;
    static int buflen = 0;

    if (len < 0)
        len = 0;

    if (len >= buflen) {
	if (buf) free (buf);
	buflen = (len < 40) ? 80 : (len * 2);
	buf = malloc (buflen+1);
	if (!buf) {
	    fprintf (stderr, "attempt to allocate %d byte scratch buffer\n", buflen + 1);
	    return NULL;
	}
    }

    strncpy (buf, s, len);
    buf[len] = '\0';

    return (buf);
}

static void
badheader(void)
{
    fprintf (stderr, "%s:  %s:%d:  bad ", ProgramName, inputFilename, lineno+1);
    parse_errors++;
}

#define badmsg0(what) { badheader(); fprintf (stderr, what); \
			   putc ('\n', stderr); }

#define badmsg(what,arg) { badheader(); fprintf (stderr, what, arg); \
			   putc ('\n', stderr); }

#define badmsgn(what,s,len) badmsg (what, copy_to_scratch (s, len))

void
initialize_map (void)
{
    map = XGetModifierMapping (dpy);
    return;
}

static void do_keycode ( char *line, int len );
static void do_keysym ( char *line, int len );
static void finish_keycodes ( const char *line, int len, KeyCode *keycodes,
			      int count );
static void do_add ( char *line, int len );
static void do_remove ( char *line, int len );
static void do_clear ( char *line, int len );
static void do_pointer ( char *line, int len );
static int get_keysym_list ( const char *line, int len, int *np, KeySym **kslistp );

static void print_opcode(union op *op);

static int skip_word ( const char *s, int len );
static int skip_chars ( const char *s, int len );
static int skip_space ( const char *s, int len );

static struct dt {
    const char *command;		/* name of input command */
    int length;				/* length of command */
    void (*proc)(char *, int);		/* handler */
} dispatch_table[] = {
    { "keycode", 7, do_keycode },
    { "keysym", 6, do_keysym },
    { "add", 3, do_add },
    { "remove", 6, do_remove },
    { "clear", 5, do_clear },
    { "pointer", 7, do_pointer },
    { NULL, 0, NULL }};

/*
 * handle_line - this routine parses the input line (which has had all leading
 * and trailing whitespace removed) and builds up the work queue.
 */

void
handle_line(char *line,		/* string to parse */
	    int len)		/* length of line */
{
    int n;
    struct dt *dtp;

    n = skip_chars (line, len);
    if (n < 0) {
	badmsg ("input line '%s'", line);
	return;
    }

    for (dtp = dispatch_table; dtp->command != NULL; dtp++) {
	if (n == dtp->length &&
	    strncmp (line, dtp->command, dtp->length) == 0) {

	    n += skip_space (line+n, len-n);
	    line += n, len -= n;

	    (*(dtp->proc)) (line, len);
	    return;
	}
    }

    fprintf (stderr, "%s:  unknown command on line %s:%d\n",
	     ProgramName, inputFilename, lineno+1);
    parse_errors++;
}

/*
 * the following routines are useful for parsing
 */

static int
skip_word (const char *s, int len)
{
    register int n;

    n = skip_chars (s, len);
    return (n + skip_space (s+n, len-n));
}

static int
skip_chars(const char *s, int len)
{
    register int i;

    if (len <= 0 || !s || *s == '\0') return (0);

    for (i = 0; i < len; i++) {
	if (isspace(s[i])) break;
    }
    return (i);
}

static int
skip_space(const char *s, int len)
{
    register int i;

    if (len <= 0 || !s || *s == '\0') return (0);

    for (i = 0; i < len; i++) {
	if (!s[i] || !isspace(s[i])) break;
    }
    return (i);
}


static int
skip_until_char(const char *s, int len, char c)
{
    register int i;

    for (i = 0; i < len; i++) {
	if (s[i] == c) break;
    }
    return (i);
}


/*
 * The action routines.
 *
 * This is where the real work gets done.  Each routine is responsible for
 * parsing its input (note that the command keyword has been stripped off)
 * and adding to the work queue.  They are also in charge of outputting
 * error messages and returning non-zero if there is a problem.
 *
 * The following global variables are available:
 *     dpy                the display descriptor
 *     work_queue         linked list of opcodes
 *     inputFilename      name of the file being processed
 *     lineno             line number of current line in input file
 */
static void
add_to_work_queue(union op *p)	/* this can become a macro someday */
{
    if (work_queue.head == NULL) {	/* nothing on the list */
	work_queue.head = work_queue.tail = p;	/* head, tail, no prev */
    } else {
	work_queue.tail->generic.next = p;  /* head okay, prev */
	work_queue.tail = p;		/* tail */
    }
    p->generic.next = NULL;

    if (verbose) {
	print_opcode (p);
    }
    return;
}

static Bool
parse_number(const char *str, unsigned long *val)
{
    const char *fmt = "%ld";

    if (*str == '0') {
	str++;
	while (isspace(*str))
	    str++;
	fmt = "%lo";
	if (*str == '\0') {
	    *val = 0;
	    return 1;
	}
	if (*str == 'x' || *str == 'X') {
	    str++;
	    fmt = "%lx";
	}
    }
    return (sscanf (str, fmt, val) == 1);
}

static Bool
parse_keysym(const char *line, int n, char **name, KeySym *keysym)
{
    *name = copy_to_scratch (line, n);
    if (!strcmp(*name, "NoSymbol")) {
	*keysym = NoSymbol;
	return (True);
    }
    *keysym = XStringToKeysym (*name);
    if (*keysym == NoSymbol && '0' <= **name && **name <= '9')
	return parse_number(*name, keysym);
    return (*keysym != NoSymbol);
}

/*
 * do_keycode - parse off lines of the form
 *
 *                 "keycode" number "=" [keysym ...]
 *                           ^
 *
 * where number is in decimal, hex, or octal.  Any number of keysyms may be
 * listed.
 */

static void
do_keycode(char *line, int len)
{
    int dummy;
    const char *fmt = "%d";
    KeyCode keycode;

    if (len < 3 || !line || *line == '\0') {  /* 5=a minimum */
	badmsg0 ("keycode input line");
	return;
    }

    /*
     * We need not bother to advance line/len past the
     * number (or the string 'any') as finish_keycodes() will
     * first advance past the '='.
     */
    if (!strncmp("any", line, 3)) {
	keycode = 0;
    } else {
	if (*line == '0') line++, len--, fmt = "%o";
	if (*line == 'x' || *line == 'X') line++, len--, fmt = "%x";

	dummy = 0;
	if (sscanf (line, fmt, &dummy) != 1 || dummy == 0) {
	    badmsg0 ("keycode value");
	    return;
	}
	keycode = (KeyCode) dummy;
	if ((int)keycode < min_keycode || (int)keycode > max_keycode) {
	    badmsg0 ("keycode value (out of range)");
	    return;
	}
    }

    finish_keycodes (line, len, &keycode, 1);
}


/*
 * do_keysym - parse off lines of the form
 *
 *                 "keysym" keysym "=" [keysym ...]
 *                          ^
 *
 * The left keysyms has to be checked for validity and evaluated.
 */

static void
do_keysym(char *line, int len)
{
    int n;
    KeyCode *keycodes;
    KeySym keysym;
    char *tmpname;

    if (len < 3 || !line || *line == '\0') {  /* a=b minimum */
	badmsg0 ("keysym input line");
	return;
    }

    n = skip_chars (line, len);
    if (n < 1) {
	badmsg0 ("target keysym name");
	return;
    }
    if (!parse_keysym(line, n, &tmpname, &keysym)) {
	badmsg ("keysym target key symbol '%s'", tmpname);
	return;
    }

    keycodes = KeysymToKeycodes (dpy, keysym, &n);
    if (n == 0) {
	badmsg ("keysym target keysym '%s', no corresponding keycodes",
		tmpname);
	return;
    }
    if (verbose) {
	int i;
	printf ("! Keysym %s (0x%lx) corresponds to keycode(s)",
		tmpname, (long) keysym);
	for (i = 0; i < n; i++)
	    printf (" 0x%x", keycodes[i]);
	printf("\n");
    }

    finish_keycodes (line, len, keycodes, n);
}

static void
finish_keycodes(const char *line, int len, KeyCode *keycodes, int count)
{
    int n;
    KeySym *kslist;
    union op *uop;
    struct op_keycode *opk;

    n = skip_until_char (line, len, '=');
    line += n, len -= n;

    if (len < 1 || *line != '=') {	/* = minimum */
	badmsg0 ("keycode command (missing keysym list),");
	return;
    }
    line++, len--;			/* skip past the = */

    n = skip_space (line, len);
    line += n, len -= n;

    /* allow empty list */
    if (get_keysym_list (line, len, &n, &kslist) < 0)
	return;

    while (--count >= 0) {
	uop = AllocStruct (union op);
	if (!uop) {
	    badmsg ("attempt to allocate a %ld byte keycode opcode",
		    (long) sizeof (struct op_keycode));
	    return;
	}
	opk = &uop->keycode;

	opk->type = doKeycode;
	opk->target_keycode = keycodes[count];
	opk->count = n;
	opk->keysyms = kslist;

	add_to_work_queue (uop);
    }

#ifdef later
    /* make sure we handle any special keys */
    check_special_keys (keycode, n, kslist);
#endif
}


/*
 * parse_modifier - convert a modifier string name to its index
 */

struct modtab modifier_table[] = {	/* keep in order so it can be index */
    { "shift", 5, 0 },
    { "lock", 4, 1 },
    { "control", 7, 2 },
    { "mod1", 4, 3 },
    { "mod2", 4, 4 },
    { "mod3", 4, 5 },
    { "mod4", 4, 6 },
    { "mod5", 4, 7 },
    { "ctrl", 4, 2 },
    { NULL, 0, 0 }};

static int
parse_modifier(char *line, int n)
{
    register int i;
    struct modtab *mt;

    /* lowercase for comparison against table */
    for (i = 0; i < n; i++) {
	if (isupper (line[i])) line[i] = tolower (line[i]);
    }

    for (mt = modifier_table; mt->name; mt++) {
	if (n == mt->length && strncmp (line, mt->name, n) == 0)
	  return (mt->value);
    }
    return (-1);
}


/*
 * do_add - parse off lines of the form
 *
 *                 add MODIFIER = keysym ...
 *                     ^
 * where the MODIFIER is one of Shift, Lock, Control, Mod[1-5] where case
 * is not important.  There should also be an alias Ctrl for control.
 */

static void
do_add(char *line, int len)
{
    int n;
    int modifier;
    KeySym *kslist;
    union op *uop;
    struct op_addmodifier *opam;

    if (len < 6 || !line || *line == '\0') {  /* Lock=a minimum */
	badmsg0 ("add modifier input line");
	return;
    }

    n = skip_chars (line, len);
    if (n < 1) {
	badmsg ("add modifier name %s", line);
	return;
    }

    modifier = parse_modifier (line, n);
    if (modifier < 0) {
	badmsgn ("add modifier name '%s', not allowed", line, n);
	return;
    }

    line += n, len -= n;
    n = skip_until_char (line, len, '=');
    if (n < 0) {
	badmsg0 ("add modifier = keysym");
	return;
    }

    n++;				/* skip = */
    n += skip_space (line+n, len-n);
    line += n, len -= n;

    if (get_keysym_list (line, len, &n, &kslist) < 0)
	return;
    if (n == 0) {
	badmsg0 ("add modifier keysym list (empty)");
	return;
    }

    uop = AllocStruct (union op);
    if (!uop) {
	badmsg ("attempt to allocate %ld byte addmodifier opcode",
		(long) sizeof (struct op_addmodifier));
	return;
    }
    opam = &uop->addmodifier;

    opam->type = doAddModifier;
    opam->modifier = modifier;
    opam->count = n;
    opam->keysyms = kslist;

    add_to_work_queue (uop);
}

#ifdef AUTO_ADD_REMOVE
/*
 * make_add - stick a single add onto the queue
 */
static void
make_add(int modifier, KeySym keysym)
{
    union op *uop;
    struct op_addmodifier *opam;

    uop = AllocStruct (union op);
    if (!uop) {
	badmsg ("attempt to allocate %ld byte addmodifier opcode",
		(long) sizeof (struct op_addmodifier));
	return;
    }
    opam = &uop->addmodifier;

    opam->type = doAddModifier;
    opam->modifier = modifier;
    opam->count = 1;
    opam->keysyms = malloc (sizeof (KeySym));
    if (!opam->keysyms) {
	badmsg ("attempt to allocate %ld byte KeySym", (long) sizeof (KeySym));
	free (opam);
	return;
    }
    opam->keysyms[0] = keysym;

    add_to_work_queue (uop);
    return;
}
#endif /* AUTO_ADD_REMOVE */


/*
 * do_remove - parse off lines of the form
 *
 *                 remove MODIFIER = oldkeysym ...
 *                        ^
 * where the MODIFIER is one of Shift, Lock, Control, Mod[1-5] where case
 * is not important.  There should also be an alias Ctrl for control.
 */

static void
do_remove(char *line, int len)
{
    int n;
    int nc;
    int i;
    int tot;
    int modifier;
    KeySym *kslist;
    KeyCode *kclist;
    union op *uop;
    struct op_removemodifier *oprm;

    if (len < 6 || !line || *line == '\0') {  /* Lock=a minimum */
	badmsg0 ("remove modifier input line");
	return;
    }

    n = skip_chars (line, len);
    if (n < 1) {
	badmsg ("remove modifier name %s", line);
	return;
    }

    modifier = parse_modifier (line, n);
    if (modifier < 0) {
	badmsgn ("remove modifier name '%s', not allowed", line, n);
	return;
    }

    line += n, len -= n;
    n = skip_until_char (line, len, '=');
    if (n < 0) {
	badmsg0 ("remove modifier = keysym");
	return;
    }

    n++;
    n += skip_space (line+n, len-n);
    line += n, len -= n;

    if (get_keysym_list (line, len, &n, &kslist) < 0)
	return;
    if (n == 0) {
	badmsg0 ("remove modifier keysym list (empty)");
	return;
    }

    /*
     * unlike the add command, we have to now evaluate the keysyms
     */

    kclist = malloc (n * sizeof (KeyCode));
    if (!kclist) {
	badmsg ("attempt to allocate %ld byte keycode list",
		(long) (n * sizeof (KeyCode)));
	free (kslist);
	return;
    }

    tot = n;
    nc = 0;
    for (i = 0; i < n; i++) {
        int num_kcs;
	KeyCode *kcs;
	kcs = KeysymToKeycodes (dpy, kslist[i], &num_kcs);
	if (num_kcs == 0) {
	    char *tmpname = XKeysymToString (kslist[i]);
	    badmsg ("keysym in remove modifier list '%s', no corresponding keycodes",
		    tmpname ? tmpname : "?");
	    continue;
	}
	if (verbose) {
	    int j;
	    char *tmpname = XKeysymToString (kslist[i]);
	    printf ("! Keysym %s (0x%lx) corresponds to keycode(s)",
		    tmpname ? tmpname : "?", (long) kslist[i]);
	    for (j = 0; j < num_kcs; j++)
		printf(" 0x%x", kcs[j]);
	    printf("\n");
	}
	if (nc + num_kcs > tot) {
	    tot = nc + num_kcs;
	    kclist = reallocfarray(kclist, tot, sizeof(KeyCode));
	    if (!kclist) {
		badmsg ("attempt to allocate %ld byte keycode list",
			(long) (tot * sizeof (KeyCode)));
		free (kslist);
		return;
	    }
	}
	while (--num_kcs >= 0)
	    kclist[nc++] = *kcs++;		/* okay, add it to list */
    }

    free (kslist);		/* all done with it */

    uop = AllocStruct (union op);
    if (!uop) {
	badmsg ("attempt to allocate %ld byte removemodifier opcode",
		(long) sizeof (struct op_removemodifier));
	free(kclist);
	return;
    }
    oprm = &uop->removemodifier;

    oprm->type = doRemoveModifier;
    oprm->modifier = modifier;
    oprm->count = nc;
    oprm->keycodes = kclist;

    add_to_work_queue (uop);
}

#ifdef AUTO_ADD_REMOVE
/*
 * make_remove - stick a single remove onto the queue
 */
static void
make_remove(int modifier, KeyCode keycode)
{
    union op *uop;
    struct op_removemodifier *oprm;

    uop = AllocStruct (union op);
    if (!uop) {
	badmsg ("attempt to allocate %ld byte removemodifier opcode",
		(long) sizeof (struct op_removemodifier));
	return;
    }
    oprm = &uop->removemodifier;

    oprm->type = doRemoveModifier;
    oprm->modifier = modifier;
    oprm->count = 1;
    oprm->keycodes = malloc (sizeof (KeyCode));
    if (!oprm->keycodes) {
	badmsg ("attempt to allocate %ld byte KeyCode",
		(long) sizeof (KeyCode));
	free (oprm);
	return;
    }
    oprm->keycodes[0] = keycode;

    add_to_work_queue (uop);
    return;
}
#endif /* AUTO_ADD_REMOVE */


/*
 * do_clear - parse off lines of the form
 *
 *                 clear MODIFIER
 *                       ^
 */

static void
do_clear(char *line, int len)
{
    int n;
    int modifier;
    union op *uop;
    struct op_clearmodifier *opcm;

    if (len < 4 || !line || *line == '\0') {  /* Lock minimum */
	badmsg0 ("clear modifier input line");
	return;
    }

    n = skip_chars (line, len);

    modifier = parse_modifier (line, n);
    if (modifier < 0) {
	badmsgn ("clear modifier name '%s'", line, n);
	return;
    }
    n += skip_space (line+n, len-n);
    if (n != len) {
	badmsgn ("extra argument '%s' to clear modifier", line+n, len-n);
	/* okay to continue */
    }

    uop = AllocStruct (union op);
    if (!uop) {
	badmsg ("attempt to allocate %ld byte clearmodifier opcode",
		(long) sizeof (struct op_clearmodifier));
	return;
    }
    opcm = &uop->clearmodifier;

    opcm->type = doClearModifier;
    opcm->modifier = modifier;

    add_to_work_queue (uop);
}

#ifndef HAVE_STRNCASECMP
static int
strncasecmp(const char *a, const char *b, int n)
{
    int i;
    int a1, b1;

    for (i = 0; i < n; i++, a++, b++) {
	if (!*a) return -1;
	if (!*b) return 1;

	if (*a != *b) {
	    a1 = (isascii(*a) && isupper(*a)) ? tolower(*a) : *a;
	    b1 = (isascii(*b) && isupper(*b)) ? tolower(*b) : *b;
	    if (a1 != b1) return b1 - a1;
	}
    }
    return 0;
}
#endif

/*
 * do_pointer = get list of numbers of the form
 *
 *                 buttons = NUMBER ...
 *                         ^
 */

static void
do_pointer(char *line, int len)
{
    int n;
    int i;
    unsigned long val;
    union op *uop;
    struct op_pointer *opp;
    unsigned char buttons[MAXBUTTONCODES];
    int nbuttons;
    char *strval;
    Bool ok;

    if (len < 2 || !line || *line == '\0') {  /* =1 minimum */
	badmsg0 ("buttons input line");
	return;
    }

    nbuttons = XGetPointerMapping (dpy, buttons, MAXBUTTONCODES);

    n = skip_space (line, len);
    line += n, len -= n;

    if (line[0] != '=') {
	badmsg0 ("buttons pointer code list, missing equal sign");
	return;
    }

    line++, len--;			/* skip = */
    n = skip_space (line, len);
    line += n, len -= n;

    i = 0;
    if (len < 7 || strncasecmp (line, "default", 7) != 0) {
	while (len > 0) {
	    n = skip_space (line, len);
	    line += n, len -= n;
	    if (line[0] == '\0') break;
	    n = skip_word (line, len);
	    if (n < 1) {
		badmsg ("skip of word in buttons line:  %s", line);
		return;
	    }
	    strval = copy_to_scratch(line, n);
	    if (strval == NULL)
		/* copy_to_scratch already printed error message */
		return;
	    ok = parse_number (strval, &val);
	    if (!ok || val >= MAXBUTTONCODES) {
		badmsg ("value %s given for buttons list", strval);
		return;
	    }
	    buttons[i++] = (unsigned char) val;
	    line += n, len -= n;
	}
    }

    if (i > 0 && i != nbuttons) {
	if (i < nbuttons) {
	    fprintf (stderr,
		     "Warning: Only changing the first %d of %d buttons.\n",
		     i, nbuttons);
	}
	else {  /* i > nbuttons */
	    fprintf (stderr,
		     "Warning: Not changing %d extra buttons beyond %d.\n",
		     i - nbuttons, nbuttons);
	}
	i = nbuttons;
    }

    uop = AllocStruct (union op);
    if (!uop) {
	badmsg ("attempt to allocate a %ld byte pointer opcode",
		(long) sizeof (struct op_pointer));
	return;
    }
    opp = &uop->pointer;

    opp->type = doPointer;
    opp->count = i;
    for (i = 0; i < opp->count; i++) {
	opp->button_codes[i] = buttons[i];
    }

    add_to_work_queue (uop);
}


/*
 * get_keysym_list - parses the rest of the line into a keysyms assumes
 * that the = sign has been parsed off but there may be leading whitespace
 *
 *                 keysym ...
 *                 ^
 *
 * this involves getting the word containing the keysym, checking its range,
 * and adding it to the list.
 */

static int
get_keysym_list(const char *line, int len, int *np, KeySym **kslistp)
{
    int havesofar, maxcanhave;
    KeySym *keysymlist;

    *np = 0;
    *kslistp = NULL;

    if (len == 0) return (0);		/* empty list */

    havesofar = 0;
    maxcanhave = 4;			/* most lists are small */
    keysymlist = malloc (maxcanhave * sizeof (KeySym));
    if (!keysymlist) {
	badmsg ("attempt to allocate %ld byte initial keysymlist",
		(long) (maxcanhave * sizeof (KeySym)));
	return (-1);
    }

    while (len > 0) {
	KeySym keysym;
	int n;
	char *tmpname;
	Bool ok;

	n = skip_space (line, len);
	line += n, len -= n;

	n = skip_chars (line, len);
	if (n < 0) {
	    badmsg0 ("keysym name list");
	    free(keysymlist);
	    return (-1);
	}

	ok = parse_keysym (line, n, &tmpname, &keysym);
	line += n, len -= n;
	if (!ok) {
	    badmsg ("keysym name '%s' in keysym list", tmpname);
	    /* do NOT return here, look for others */
	    continue;
	}

	/*
	 * Do NOT test to see if the keysym translates to a keycode or you
	 * won't be able to assign new ones....
	 */

	/* grow the list bigger if necessary */
	if (havesofar >= maxcanhave) {
	    maxcanhave *= 2;
	    keysymlist = reallocfarray(keysymlist, maxcanhave, sizeof(KeySym));
	    if (!keysymlist) {
		badmsg ("attempt to grow keysym list to %ld bytes",
			(long) (maxcanhave * sizeof (KeySym)));
		return (-1);
	    }
	}

	/* and add it to the list */
	keysymlist[havesofar++] = keysym;
    }

    *kslistp = keysymlist;
    *np = havesofar;
    return (0);
}


#ifdef later
/*
 * check_special_keys - run through list of keysyms and generate "add" or
 * "remove" commands for for any of the key syms that appear in the modifier
 * list.  this involves running down the modifier map which is an array of
 * 8 by map->max_keypermod keycodes.
 */

static void
check_special_keys(KeyCode keycode, int n, KeySym *kslist)
{
    int i;				/* iterator variable */
    KeyCode *kcp;			/* keycode pointer */

    /*
     * walk the modifiermap array.  since its dimensions are not known at
     * compile time, we have to walk it by hand instead of indexing.  this
     * is why it is initialized outside the loop, but incremented inside the
     * second loop.
     */

    kcp = map->modifiermap;		/* start at beginning and iterate */
    for (i = 0; i < 8; i++) {		/* there are 8 modifier keys */
	int j;

	for (j = 0; j < map->max_keypermod; j++, kcp++) {
	    KeySym keysym;
	    int k;

	    if (!*kcp) continue;	/* only non-zero entries significant */

	    /*
	     * check to see if the target keycode is already a modifier; if so,
	     * then we have to remove it
	     */
	    if (keycode == *kcp) {
		make_remove (i, keycode);
	    }

	    /*
	     * now, check to see if any of the keysyms map to keycodes
	     * that are in the modifier list
	     */
	    for (k = 0; k < n; k++) {
		KeyCodes kc;

		kc = XKeysymToKeycode (dpy, kslist[k]);
		if (kc == *kcp) {	/* yup, found one */
		    /*
		     * have to generate a remove of the CURRENT keycode
		     * and then an add of the new KEYCODE
		     */
		    make_remove (i, kc);  /* modifier, keycode */
		    make_add (i, kslist[k]);  /* modifier, keysym */
		}
	    }
	}
    }
    return;
}
#endif

/*
 * print_work_queue - disassemble the work queue and print it on stdout
 */

void
print_work_queue(void)
{
    union op *op;

    printf ("! dump of work queue\n");
    for (op = work_queue.head; op; op = op->generic.next) {
	print_opcode (op);
    }
    return;
}

static void
print_opcode(union op *op)
{
    int i;

    printf ("        ");
    switch (op->generic.type) {
      case doKeycode:
	if (op->keycode.target_keycode)
	    printf ("keycode 0x%lx =", (long) op->keycode.target_keycode);
	else
	    printf ("keycode any =");
	for (i = 0; i < op->keycode.count; i++) {
	    char *name = XKeysymToString (op->keycode.keysyms[i]);

	    printf (" %s", name ? name : "BADKEYSYM");
	}
	printf ("\n");
	break;
      case doAddModifier:
	printf ("add %s =", modifier_table[op->addmodifier.modifier].name);
	for (i = 0; i < op->addmodifier.count; i++) {
	    char *name = XKeysymToString (op->addmodifier.keysyms[i]);
	    printf (" %s", name ? name : "BADKEYSYM");
	}
	printf ("\n");
	break;
      case doRemoveModifier:
	printf ("remove %s = ",
		modifier_table[op->removemodifier.modifier].name);
	for (i = 0; i < op->removemodifier.count; i++) {
	    printf (" 0x%lx", (long) op->removemodifier.keycodes[i]);
	}
	printf ("\n");
	break;
      case doClearModifier:
	printf ("clear %s\n", modifier_table[op->clearmodifier.modifier].name);
	break;
      case doPointer:
	printf ("pointer = ");
	if (op->pointer.count == 0)
	    printf(" default");
	else for (i=0; i < op->pointer.count; i++)
	    printf(" %d", op->pointer.button_codes[i]);
	printf ("\n");
	break;
      default:
	printf ("! unknown opcode %d\n", op->generic.type);
	break;
    }				/* end switch */
    return;
}

/*
 * execute_work_queue - do the real meat and potatoes now that we know what
 * we need to do and that all of the input is correct.
 */
static int exec_keycode ( struct op_keycode *opk );
static int exec_add ( struct op_addmodifier *opam );
static int exec_remove ( struct op_removemodifier *oprm );
static int exec_clear ( struct op_clearmodifier *opcm );
static int exec_pointer ( struct op_pointer *opp );


int
execute_work_queue (void)
{
    union op *op;
    int errors;
    Bool update_map = False;
    int dosync;

    if (verbose) {
	printf ("!\n");
	printf ("! executing work queue\n");
	printf ("!\n");
    }

    errors = 0;
    dosync = 0;

    for (op = work_queue.head; op; op = op->generic.next) {
	if (verbose) print_opcode (op);

	/* check to see if we have to update the keyboard mapping */
	if (dosync &&
	    (dosync < 0 ||
	     op->generic.type != doKeycode ||
	     !op->keycode.target_keycode)) {
	    XSync (dpy, 0);
	    while (XEventsQueued (dpy, QueuedAlready) > 0) {
		XEvent event;
		XNextEvent (dpy, &event);
		if (event.type == MappingNotify) {
		    /* read all MappingNotify events */
		    while (XCheckTypedEvent (dpy, MappingNotify, &event)) ;
		    XRefreshKeyboardMapping (&event.xmapping);
		} else {
		    fprintf (stderr, "%s:  unknown event %ld\n",
		    	     ProgramName, (long) event.type);
		}
	    }
	}
	dosync = 0;
	switch (op->generic.type) {
	  case doKeycode:
	    if (exec_keycode (&op->keycode) < 0) errors++;
	    if (op->keycode.target_keycode)
		dosync = 1;
	    else
		dosync = -1;
	    break;
	  case doAddModifier:
	    if (exec_add (&op->addmodifier) < 0) errors++;
	    else update_map = True;
	    break;
	  case doRemoveModifier:
	    if (exec_remove (&op->removemodifier) < 0) errors++;
	    else update_map = True;
	    break;
	  case doClearModifier:
	    if (exec_clear (&op->clearmodifier) < 0) errors++;
	    else update_map = True;
	    break;
	  case doPointer:
	    if (exec_pointer (&op->pointer) < 0) errors++;
	    break;
	  default:
	    fprintf (stderr, "%s:  unknown opcode %d\n",
		     ProgramName, op->generic.type);
	    break;
	}
    }

    if (update_map) {
	if (UpdateModifierMapping (map) < 0) errors++;
    }

    return (errors > 0 ? -1 : 0);
}

static int
exec_keycode(struct op_keycode *opk)
{
    if (!opk->target_keycode) {
	int i, j;
	KeyCode free;
	if (!opk->count)
	    return (0);
	free = 0;
	for (i = min_keycode; i <= max_keycode; i++) {
	    for (j = 0; j < opk->count; j++) {
		if (XKeycodeToKeysym(dpy, (KeyCode) i, j) != opk->keysyms[j])
		    break;
	    }
	    if (j >= opk->count)
		return (0);
	    if (free)
		continue;
	    for (j = 0; j < 8; j++) {
		if (XKeycodeToKeysym(dpy, (KeyCode) i, j) != None)
		    break;
	    }
	    if (j >= 8)
		free = i;
	}
	if (!free) {
	    fprintf(stderr, "%s: no available keycode for assignment\n",
		    ProgramName);
	    return (-1);
	}
	XChangeKeyboardMapping (dpy, free, opk->count, opk->keysyms, 1);
    } else if (opk->count == 0) {
	KeySym dummy = NoSymbol;
	XChangeKeyboardMapping (dpy, opk->target_keycode, 1,
				&dummy, 1);
    } else {
	XChangeKeyboardMapping (dpy, opk->target_keycode, opk->count,
				opk->keysyms, 1);
    }
    return (0);
}

static int
exec_add(struct op_addmodifier *opam)
{
    int i;
    int status;

    status = 0;
    for (i = 0; i < opam->count; i++) {
	int num_kcs;
	KeyCode *kcs;

	kcs = KeysymToKeycodes (dpy, opam->keysyms[i], &num_kcs);
	if (num_kcs == 0)
	    status = -1;
	while (--num_kcs >= 0) {
	    if (AddModifier (&map, *kcs++, opam->modifier) < 0)
		status = -1;
	}
    }
    return (status);
}

static int
exec_remove(struct op_removemodifier *oprm)
{
    int i;
    int status;

    status = 0;
    for (i = 0; i < oprm->count; i++) {
	if (RemoveModifier (&map, oprm->keycodes[i], oprm->modifier) < 0)
	  status = -1;
    }
    return (status);
}

static int
exec_clear(struct op_clearmodifier *opcm)
{
    return (ClearModifier (&map, opcm->modifier));
}


static int
exec_pointer(struct op_pointer *opp)
{
    return (SetPointerMap (opp->button_codes, opp->count));
}

void
print_modifier_map(void)
{
    PrintModifierMapping (map, stdout);
    return;
}

void
print_key_table(Bool exprs)
{
    PrintKeyTable (exprs, stdout);
    return;
}

void
print_pointer_map(void)
{
    PrintPointerMap (stdout);
    return;
}