summary refs log tree commit diff
path: root/Src/Zle/zle_thingy.c
blob: c252eee1e6b76ce4e37bfc7d498a95eb995047f9 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
/*
 * zle_thingy.c - thingies
 *
 * This file is part of zsh, the Z shell.
 *
 * Copyright (c) 1992-1997 Paul Falstad
 * All rights reserved.
 *
 * Permission is hereby granted, without written agreement and without
 * license or royalty fees, to use, copy, modify, and distribute this
 * software and to distribute modified versions of this software for any
 * purpose, provided that the above copyright notice and the following
 * two paragraphs appear in all copies of this software.
 *
 * In no event shall Paul Falstad or the Zsh Development Group be liable
 * to any party for direct, indirect, special, incidental, or consequential
 * damages arising out of the use of this software and its documentation,
 * even if Paul Falstad and the Zsh Development Group have been advised of
 * the possibility of such damage.
 *
 * Paul Falstad and the Zsh Development Group specifically disclaim any
 * warranties, including, but not limited to, the implied warranties of
 * merchantability and fitness for a particular purpose.  The software
 * provided hereunder is on an "as is" basis, and Paul Falstad and the
 * Zsh Development Group have no obligation to provide maintenance,
 * support, updates, enhancements, or modifications.
 *
 */

#include "zle.mdh"
#include "zle_thingy.pro"

/*
 * Thingies:
 *
 * From the user's point of view, a thingy is just a string.  Internally,
 * the thingy is a struct thingy; these structures are in a hash table
 * indexed by the string the user sees.  This hash table contains all
 * thingies currently referenced anywhere; each has a reference count,
 * and is deleted when it becomes unused.  Being the name of a function
 * counts as a reference.
 *
 * The DISABLED flag on a thingy indicates that it is not the name of a
 * widget.  This makes it easy to generate completion lists;
 * looking only at the `enabled' nodes makes the thingy table look like
 * a table of widgets.
 */

/* Hashtable of thingies.  Enabled nodes are those that refer to widgets. */

/**/
mod_export HashTable thingytab;

/**********************************/
/* hashtable management functions */
/**********************************/

/**/
static void
createthingytab(void)
{
    thingytab = newhashtable(199, "thingytab", NULL);

    thingytab->hash        = hasher;
    thingytab->emptytable  = emptythingytab;
    thingytab->filltable   = NULL;
    thingytab->cmpnodes    = strcmp;
    thingytab->addnode     = addhashnode;
    thingytab->getnode     = gethashnode;
    thingytab->getnode2    = gethashnode2;
    thingytab->removenode  = removehashnode;
    thingytab->disablenode = NULL;
    thingytab->enablenode  = NULL;
    thingytab->freenode    = freethingynode;
    thingytab->printnode   = NULL;
}

/**/
static void
emptythingytab(UNUSED(HashTable ht))
{
    /* This will only be called when deleting the thingy table, which *
     * is only done to unload the zle module.  A normal emptytable()  *
     * function would free all the thingies, but we don't want to do  *
     * that because some of them are the known thingies in the fixed  *
     * `thingies' table.  As the module cleanup code deletes all the  *
     * keymaps and so on before deleting the thingy table, we can     *
     * just remove the user-defined widgets and then be sure that     *
     * *all* the thingies left are the fixed ones.  This has the side *
     * effect of freeing all resources used by user-defined widgets.  */
    scanhashtable(thingytab, 0, 0, DISABLED, scanemptythingies, 0);
}

/**/
static void
scanemptythingies(HashNode hn, UNUSED(int flags))
{
    Thingy t = (Thingy) hn;

    /* Mustn't unbind internal widgets -- we wouldn't want to free the *
     * memory they use.                                                */
    if(!(t->widget->flags & WIDGET_INT))
	unbindwidget(t, 1);
}

/**/
static Thingy
makethingynode(void)
{
    Thingy t = (Thingy) zshcalloc(sizeof(*t));

    t->flags = DISABLED;
    return t;
}

/**/
static void
freethingynode(HashNode hn)
{
    Thingy th = (Thingy) hn;

    zsfree(th->nam);
    zfree(th, sizeof(*th));
}

/************************/
/* referencing thingies */
/************************/

/* It is important to maintain the reference counts on thingies.  When *
 * copying a reference to a thingy, wrap the copy in refthingy(), to   *
 * increase its reference count.  When removing a reference,           *
 * unrefthingy() it.  Both of these functions handle NULL arguments    *
 * correctly.                                                          */

/**/
mod_export Thingy
refthingy(Thingy th)
{
    if(th)
	th->rc++;
    return th;
}

/**/
void
unrefthingy(Thingy th)
{
    if(th && !--th->rc)
	thingytab->freenode(thingytab->removenode(thingytab, th->nam));
}

/* Use rthingy() to turn a string into a thingy.  It increases the reference *
 * count, after creating the thingy structure if necessary.                  */

/**/
Thingy
rthingy(char *nam)
{
    Thingy t = (Thingy) thingytab->getnode2(thingytab, nam);

    if(!t)
	thingytab->addnode(thingytab, ztrdup(nam), t = makethingynode());
    return refthingy(t);
}

/**/
Thingy
rthingy_nocreate(char *nam)
{
    Thingy t = (Thingy) thingytab->getnode2(thingytab, nam);

    if(!t)
	return NULL;
    return refthingy(t);
}

/***********/
/* widgets */
/***********/

/*
 * Each widget is attached to one or more thingies.  Each thingy
 * names either zero or one widgets.  Thingies that name a widget
 * are treated as being referenced.  The widget type, flags and pointer
 * are stored in a separate structure pointed to by the thingies.  Each
 * thingy also has a pointer to the `next' thingy (in a circular list)
 * that references the same widget.  The DISABLED flag is unset in these
 * thingies.
 */

/* Bind a widget to a thingy.  The thingy's reference count must already *
 * have been incremented.  The widget may already be bound to other      *
 * thingies; if it is not, then its `first' member must be NULL.  Return *
 * is 0 on success, or -1 if the thingy has the TH_IMMORTAL flag set.    */

/**/
static int
bindwidget(Widget w, Thingy t)
{
    if(t->flags & TH_IMMORTAL) {
	unrefthingy(t);
	return -1;
    }
    if(!(t->flags & DISABLED)) {
	if(t->widget == w)
	    return 0;
	unbindwidget(t, 1);
    }
    if(w->first) {
	t->samew = w->first->samew;
	w->first->samew = t;
    } else {
	w->first = t;
	t->samew = t;
    }
    t->widget = w;
    t->flags &= ~DISABLED;
    return 0;
}

/* Unbind a widget from a thingy.  This decrements the thingy's reference *
 * count.  The widget will be destroyed if this is its last name.         *
 * TH_IMMORTAL thingies won't be touched, unless override is non-zero.    *
 * Returns 0 on success, or -1 if the thingy is protected.  If the thingy *
 * doesn't actually reference a widget, this is considered successful.    */

/**/
static int
unbindwidget(Thingy t, int override)
{
    Widget w;

    if(t->flags & DISABLED)
	return 0;
    if(!override && (t->flags & TH_IMMORTAL))
	return -1;
    w = t->widget;
    if(t->samew == t)
	freewidget(w);
    else {
	Thingy p;
	for(p = w->first; p->samew != t; p = p->samew) ;
	w->first = p;   /* optimised for deletezlefunction() */
	p->samew = t->samew;
    }
    t->flags &= ~TH_IMMORTAL;
    t->flags |= DISABLED;
    unrefthingy(t);
    return 0;
}

/* Free a widget. */

/**/
static void
freewidget(Widget w)
{
    if (w->flags & WIDGET_NCOMP) {
	zsfree(w->u.comp.wid);
	zsfree(w->u.comp.func);
    } else if(!(w->flags & WIDGET_INT))
	zsfree(w->u.fnnam);
    zfree(w, sizeof(*w));
}

/* Add am internal widget provided by a module.  The name given is the  *
 * canonical one, which must not begin with a dot.  The widget is first *
 * bound to the dotted canonical name; if that name is already taken by *
 * an internal widget, failure is indicated.  The same widget is then   *
 * bound to the canonical name, and a pointer to the widget structure   *
 * returned.                                                            */

/**/
mod_export Widget
addzlefunction(char *name, ZleIntFunc ifunc, int flags)
{
    VARARR(char, dotn, strlen(name) + 2);
    Widget w;
    Thingy t;

    if(name[0] == '.')
	return NULL;
    dotn[0] = '.';
    strcpy(dotn + 1, name);
    t = (Thingy) thingytab->getnode(thingytab, dotn);
    if(t && (t->flags & TH_IMMORTAL))
	return NULL;
    w = zalloc(sizeof(*w));
    w->flags = WIDGET_INT | flags;
    w->first = NULL;
    w->u.fn = ifunc;
    t = rthingy(dotn);
    bindwidget(w, t);
    t->flags |= TH_IMMORTAL;
    bindwidget(w, rthingy(name));
    return w;
}

/* Delete an internal widget provided by a module.  Don't try to delete *
 * a widget from the fixed table -- it would be bad.  (Thanks, Egon.)   */

/**/
mod_export void
deletezlefunction(Widget w)
{
    Thingy p, n;

    p = w->first;
    while(1) {
	n = p->samew;
	if(n == p) {
	    unbindwidget(p, 1);
	    return;
	}
	unbindwidget(p, 1);
	p = n;
    }
}

/***************/
/* zle builtin */
/***************/

/*
 * The available operations are:
 *
 *   -l   list widgets/test for existence
 *   -D   delete widget names
 *   -A   link the two named widgets (2 arguments)
 *   -C   create completion widget (3 arguments)
 *   -N   create new user-defined widget (1 or 2 arguments)
 *        invoke a widget (1 argument)
 */

/**/
int
bin_zle(char *name, char **args, Options ops, UNUSED(int func))
{
    static struct opn {
	char o;
	int (*func) _((char *, char **, Options, char));
	int min, max;
    } const opns[] = {
	{ 'l', bin_zle_list, 0, -1 },
	{ 'D', bin_zle_del,  1, -1 },
	{ 'A', bin_zle_link, 2,  2 },
	{ 'N', bin_zle_new,  1,  2 },
	{ 'C', bin_zle_complete, 3, 3 },
	{ 'R', bin_zle_refresh, 0, -1 },
	{ 'M', bin_zle_mesg, 1, 1 },
	{ 'U', bin_zle_unget, 1, 1 },
	{ 'K', bin_zle_keymap, 1, 1 },
	{ 'I', bin_zle_invalidate, 0, 0 },
	{ 'F', bin_zle_fd, 0, 2 },
	{ 0,   bin_zle_call, 0, -1 },
    };
    struct opn const *op, *opp;
    int n;

    /* select operation and ensure no clashing arguments */
    for(op = opns; op->o && !OPT_ISSET(ops,STOUC(op->o)); op++) ;
    if(op->o)
	for(opp = op; (++opp)->o; )
	    if(OPT_ISSET(ops,STOUC(opp->o))) {
		zwarnnam(name, "incompatible operation selection options",
		    NULL, 0);
		return 1;
	    }

    /* check number of arguments */
    for(n = 0; args[n]; n++) ;
    if(n < op->min) {
	zwarnnam(name, "not enough arguments for -%c", NULL, op->o);
	return 1;
    } else if(op->max != -1 && n > op->max) {
	zwarnnam(name, "too many arguments for -%c", NULL, op->o);
	return 1;
    }

    /* pass on the work to the operation function */
    return op->func(name, args, ops, op->o);
}

/**/
static int
bin_zle_list(UNUSED(char *name), char **args, Options ops, UNUSED(char func))
{
    if (!*args) {
	scanhashtable(thingytab, 1, 0, DISABLED, scanlistwidgets,
		      (OPT_ISSET(ops,'a') ? -1 : OPT_ISSET(ops,'L')));
	return 0;
    } else {
	int ret = 0;
	Thingy t;

	for (; *args && !ret; args++) {
	    if (!(t = (Thingy) thingytab->getnode2(thingytab, *args)) ||
		(!OPT_ISSET(ops,'a') && (t->widget->flags & WIDGET_INT)))
		ret = 1;
	}
	return ret;
    }
}

/**/
static int
bin_zle_refresh(UNUSED(char *name), char **args, Options ops, UNUSED(char func))
{
    char *s = statusline;
    int sl = statusll, ocl = clearlist;

    if (!zleactive)
	return 1;
    statusline = NULL;
    statusll = 0;
    if (*args) {
	if (**args) {
	    statusline = *args;
	    statusll = strlen(statusline);
	}
	if (*++args) {
	    LinkList l = newlinklist();
	    int zmultsav = zmult;

	    for (; *args; args++)
		addlinknode(l, *args);

	    zmult = 1;
	    listlist(l);
	    if (statusline)
		lastlistlen++;
	    showinglist = clearlist = 0;
	    zmult = zmultsav;
	} else if (OPT_ISSET(ops,'c')) {
	    clearlist = 1;
	    lastlistlen = 0;
	}
    } else if (OPT_ISSET(ops,'c')) {
	clearlist = listshown = 1;
	lastlistlen = 0;
    }
    zrefresh();

    clearlist = ocl;
    statusline = s;
    statusll = sl;
    return 0;
}

/**/
static int
bin_zle_mesg(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    if (!zleactive) {
	zwarnnam(name, "can only be called from widget function", NULL, 0);
	return 1;
    }
    showmsg(*args);
    if (sfcontext != SFC_WIDGET)
	zrefresh();
    return 0;
}

/**/
static int
bin_zle_unget(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    char *b = *args, *p = b + strlen(b);

    if (!zleactive) {
	zwarnnam(name, "can only be called from widget function", NULL, 0);
	return 1;
    }
    while (p > b)
	ungetkey((int) *--p);
    return 0;
}

/**/
static int
bin_zle_keymap(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    if (!zleactive) {
	zwarnnam(name, "can only be called from widget function", NULL, 0);
	return 1;
    }
    return selectkeymap(*args, 0);
}

/**/
static void
scanlistwidgets(HashNode hn, int list)
{
    Thingy t = (Thingy) hn;
    Widget w = t->widget;

    if(list < 0) {
	printf("%s\n", hn->nam);
	return;
    }
    if(w->flags & WIDGET_INT)
	return;
    if(list) {
	printf("zle -%c ", (w->flags & WIDGET_NCOMP) ? 'C' : 'N');
	if(t->nam[0] == '-')
	    fputs("-- ", stdout);
	quotedzputs(t->nam, stdout);
	if (w->flags & WIDGET_NCOMP) {
	    fputc(' ', stdout);
	    quotedzputs(w->u.comp.wid, stdout);
	    fputc(' ', stdout);
	    quotedzputs(w->u.comp.func, stdout);
	} else if(strcmp(t->nam, w->u.fnnam)) {
	    fputc(' ', stdout);
	    quotedzputs(w->u.fnnam, stdout);
	}
    } else {
	nicezputs(t->nam, stdout);
	if (w->flags & WIDGET_NCOMP) {
	    fputs(" -C ", stdout);
	    nicezputs(w->u.comp.wid, stdout);
	    fputc(' ', stdout);
	    nicezputs(w->u.comp.func, stdout);
	} else if(strcmp(t->nam, w->u.fnnam)) {
	    fputs(" (", stdout);
	    nicezputs(w->u.fnnam, stdout);
	    fputc(')', stdout);
	}
    }
    putchar('\n');
}

/**/
static int
bin_zle_del(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    int ret = 0;

    do {
	Thingy t = (Thingy) thingytab->getnode(thingytab, *args);
	if(!t) {
	    zwarnnam(name, "no such widget `%s'", *args, 0);
	    ret = 1;
	} else if(unbindwidget(t, 0)) {
	    zwarnnam(name, "widget name `%s' is protected", *args, 0);
	    ret = 1;
	}
    } while(*++args);
    return ret;
}

/**/
static int
bin_zle_link(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    Thingy t = (Thingy) thingytab->getnode(thingytab, args[0]);

    if(!t) {
	zwarnnam(name, "no such widget `%s'", args[0], 0);
	return 1;
    } else if(bindwidget(t->widget, rthingy(args[1]))) {
	zwarnnam(name, "widget name `%s' is protected", args[1], 0);
	return 1;
    }
    return 0;

}

/**/
static int
bin_zle_new(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    Widget w = zalloc(sizeof(*w));

    w->flags = 0;
    w->first = NULL;
    w->u.fnnam = ztrdup(args[1] ? args[1] : args[0]);
    if(!bindwidget(w, rthingy(args[0])))
	return 0;
    freewidget(w);
    zwarnnam(name, "widget name `%s' is protected", args[0], 0);
    return 1;
}

/**/
static int
bin_zle_complete(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    Thingy t;
    Widget w, cw;

    if (!require_module(name, "zsh/complete", 0, 0)) {
	zwarnnam(name, "can't load complete module", NULL, 0);
	return 1;
    }
    t = rthingy((args[1][0] == '.') ? args[1] : dyncat(".", args[1]));
    cw = t->widget;
    unrefthingy(t);
    if (!cw || !(cw->flags & ZLE_ISCOMP)) {
	zwarnnam(name, "invalid widget `%s'", args[1], 0);
	return 1;
    }
    w = zalloc(sizeof(*w));
    w->flags = WIDGET_NCOMP|ZLE_MENUCMP|ZLE_KEEPSUFFIX;
    w->first = NULL;
    w->u.comp.fn = cw->u.fn;
    w->u.comp.wid = ztrdup(args[1]);
    w->u.comp.func = ztrdup(args[2]);
    if (bindwidget(w, rthingy(args[0]))) {
	freewidget(w);
	zwarnnam(name, "widget name `%s' is protected", args[0], 0);
	return 1;
    }
    hascompwidgets++;

    return 0;
}

/**/
static int
zle_usable()
{
    return zleactive && !incompctlfunc && !incompfunc
#if 0
	/*
	 * PWS experiment: commenting this out allows zle widgets
	 * in signals, hooks etc.  I'm not sure if this has a down side;
	 * it ought to be that zleactive is good enough to test whether
	 * widgets are callable.
	 */
	&& sfcontext == SFC_WIDGET
#endif
	   ;
}

/**/
static int
bin_zle_call(char *name, char **args, UNUSED(Options ops), UNUSED(char func))
{
    Thingy t;
    struct modifier modsave;
    int ret, saveflag = 0;
    char *wname = *args++;

    if (!wname) {
	if (saveflag)
	    zmod = modsave;
	return !zle_usable();
    }
    if(!zle_usable()) {
	zwarnnam(name, "widgets can only be called when ZLE is active",
	    NULL, 0);
	return 1;
    }

    while (*args && **args == '-') {
	char *num;
	if (!args[0][1] || args[0][1] == '-') {
	    args++;
	    break;
	}
	while (*++(*args)) {
	    switch (**args) {
	    case 'n':
		num = args[0][1] ? args[0]+1 : args[1];
		if (!num) {
		    zwarnnam(name, "number expected after -%c", NULL, **args);
		    return 1;
		}
		if (!args[0][1])
		    *++args = "" - 1;
		modsave = zmod;
		saveflag = 1;
		zmod.mult = atoi(num);
		zmod.flags |= MOD_MULT;
		break;
	    case 'N':
		modsave = zmod;
		saveflag = 1;
		zmod.mult = 1;
		zmod.flags &= ~MOD_MULT;
		break;
	    default:
		zwarnnam(name, "unknown option: %s", *args, 0);
		return 1;
	    }
	}
	args++;
    }

    t = rthingy(wname);
    ret = execzlefunc(t, args);
    unrefthingy(t);
    if (saveflag)
	zmod = modsave;
    return ret;
}

/**/
static int
bin_zle_invalidate(UNUSED(char *name), UNUSED(char **args), UNUSED(Options ops), UNUSED(char func))
{
    /*
     * Trash zle if trashable, but only indicate that zle is usable
     * if it's possible to call a zle widget next.  This is not
     * true if a completion widget is active.
     */
    if (zleactive) {
	if (!trashedzle)
	    trashzle();
	return !zle_usable();
    } else
	return 1;
}

/**/
static int
bin_zle_fd(char *name, char **args, Options ops, UNUSED(char func))
{
    int fd = 0, i, found = 0;
    char *endptr;

    if (*args) {
	fd = (int)zstrtol(*args, &endptr, 10);

	if (*endptr || fd < 0) {
	    zwarnnam(name, "Bad file descriptor number for -F: %s", *args, 0);
	    return 1;
	}
    }

    if (OPT_ISSET(ops,'L') || !*args) {
	/* Listing handlers. */
	if (*args && args[1]) {
	    zwarnnam(name, "too many arguments for -FL", NULL, 0);
	    return 1;
	}
	for (i = 0; i < nwatch; i++) {
	    if (*args && watch_fds[i] != fd)
		continue;
	    found = 1;
	    printf("%s -F %d %s\n", name, watch_fds[i], watch_funcs[i]);
	}
	/* only return status 1 if fd given and not found */
	return *args && !found;
    }

    if (args[1]) {
	/* Adding or replacing a handler */
	char *funcnam = ztrdup(args[1]);
	if (nwatch) {
	    for (i = 0; i < nwatch; i++) {
		if (watch_fds[i] == fd) {
		    zsfree(watch_funcs[i]);
		    watch_funcs[i] = funcnam;
		    found = 1;
		    break;
		}
	    }
	}
	if (!found) {
	    /* zrealloc handles NULL pointers, so OK for first time through */
	    int newnwatch = nwatch+1;
	    watch_fds = (int *)zrealloc(watch_fds, 
					newnwatch * sizeof(int));
	    watch_funcs = (char **)zrealloc(watch_funcs,
					    (newnwatch+1) * sizeof(char *));
	    watch_fds[nwatch] = fd;
	    watch_funcs[nwatch] = funcnam;
	    watch_funcs[newnwatch] = NULL;
	    nwatch = newnwatch;
	}
    } else {
	/* Deleting a handler */
	for (i = 0; i < nwatch; i++) {
	    if (watch_fds[i] == fd) {
		int newnwatch = nwatch-1;
		int *new_fds;
		char **new_funcs;

		zsfree(watch_funcs[i]);
		if (newnwatch) {
		    new_fds = zalloc(newnwatch*sizeof(int));
		    new_funcs = zalloc((newnwatch+1)*sizeof(char*));
		    if (i) {
			memcpy(new_fds, watch_fds, i*sizeof(int));
			memcpy(new_funcs, watch_funcs, i*sizeof(char *));
		    }
		    if (i < newnwatch) {
			memcpy(new_fds+i, watch_fds+i+1,
			       (newnwatch-i)*sizeof(int));
			memcpy(new_funcs+i, watch_funcs+i+1,
			       (newnwatch-i)*sizeof(char *));
		    }
		    new_funcs[newnwatch] = NULL;
		} else {
		    new_fds = NULL;
		    new_funcs = NULL;
		}
		zfree(watch_fds, nwatch*sizeof(int));
		zfree(watch_funcs, (nwatch+1)*sizeof(char *));
		watch_fds = new_fds;
		watch_funcs = new_funcs;
		nwatch = newnwatch;
		found = 1;
		break;
	    }
	}
	if (!found) {
	    zwarnnam(name, "No handler installed for fd %d", NULL, fd);
	    return 1;
	}
    }

    return 0;
}

/*******************/
/* initialiasation */
/*******************/

/**/
void
init_thingies(void)
{
    Thingy t;

    createthingytab();
    for(t = thingies; t->nam; t++)
	thingytab->addnode(thingytab, t->nam, t);
}