fitstab.c 19.6 KB
Newer Older
Emmanuel Bertin's avatar
Emmanuel Bertin committed
1
/*
2
3
4
5
6
7
8
9
10
11
12
*				fitstab.c
*
* Handle FITS extensions and tables.
*
*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
*
*	This file part of:	AstrOmatic FITS/LDAC library
*
*	Copyright:		(C) 1998-2010 IAP/CNRS/UPMC
*				(C) 1997 European Southern Observatory
*				(C) 1995,1996 Sterrewacht Leiden
Emmanuel Bertin's avatar
Emmanuel Bertin committed
13
*
14
*	Author:			Emmanuel Bertin (IAP)
Emmanuel Bertin's avatar
Emmanuel Bertin committed
15
*
16
*	License:		GNU General Public License
Emmanuel Bertin's avatar
Emmanuel Bertin committed
17
*
18
19
20
21
22
23
24
25
26
27
28
*	AstrOmatic software is free software: you can redistribute it and/or
*	modify it under the terms of the GNU General Public License as
*	published by the Free Software Foundation, either version 3 of the
*	License, or (at your option) any later version.
*	AstrOmatic software is distributed in the hope that it will be useful,
*	but WITHOUT ANY WARRANTY; without even the implied warranty of
*	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
*	GNU General Public License for more details.
*	You should have received a copy of the GNU General Public License
*	along with AstrOmatic software.
*	If not, see <http://www.gnu.org/licenses/>.
Emmanuel Bertin's avatar
Emmanuel Bertin committed
29
*
30
*	Last modified:		09/10/2010
Emmanuel Bertin's avatar
Emmanuel Bertin committed
31
*
32
*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
Emmanuel Bertin's avatar
Emmanuel Bertin committed
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55

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

#include	<stdio.h>
#include	<stdlib.h>
#include	<string.h>

#include	"fitscat_defs.h"
#include	"fitscat.h"

/****** about_tab **************************************************************
PROTO	int about_tab(catstruct *cat, char *tabname, FILE *stream)
PURPOSE	Print information concerning a tab structure.
INPUT	Pointer to the input catalog,
	table name,
	an output stream.
OUTPUT	RETURN_OK if the table was found, RETURN_ERROR otherwise.
NOTES	-.
AUTHOR	E.R. Deul(Leiden observatory),
	E. Bertin (IAP & Leiden observatory): return value modified.
	E.R. Deul(Leiden observatory): output units
56
VERSION	28/10/2009
Emmanuel Bertin's avatar
Emmanuel Bertin committed
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
 ***/
int about_tab(catstruct *cat, char *tabname, FILE *stream)
{
   tabstruct *tab;
   keystruct *key;
   int		i, j;

   if ((tab = name_to_tab(cat, tabname, 0))) {
       fprintf(stream, "Table %s\n", tabname);
      for (i=0, key=tab->key; i<tab->nkey; i++,key=key->nextkey)
    {
    fprintf(stream,
	"******	Key #%d\n", i+1);
    fprintf(stream,
	"	Key name:...............%s\n", key->name);
    fprintf(stream,
	"	Key comment:............%s\n", key->comment);
    fprintf(stream,
	"	Key type:...............");
    switch (key->ttype) {
    case T_BYTE: fprintf(stream,"Byte"); break;
    case T_SHORT: fprintf(stream,"Short Int"); break;
    case T_LONG: fprintf(stream,"Long Int"); break;
80
    case T_LONGLONG: fprintf(stream,"Long Long Int"); break;
Emmanuel Bertin's avatar
Emmanuel Bertin committed
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
    case T_FLOAT: fprintf(stream,"Float"); break;
    case T_DOUBLE: fprintf(stream,"Double"); break;
    case T_STRING: fprintf(stream,"String"); break;
    }
    fprintf(stream,"\n");
    fprintf(stream,
	"	Key dimension:..........%d ", key->naxis);
    if (key->naxis) fprintf(stream, "(");
    for (j=0;j<key->naxis;j++) {
       if (j>0) fprintf(stream, " ");
       fprintf(stream, "%d", key->naxisn[j]);
    }
    if (key->naxis) fprintf(stream, ")");
    fprintf(stream, "\n");
    if (key->unit[0] != '\0') 
       fprintf(stream,
	"	Key unit:...............%s\n", key->unit);
    }
   } else return RETURN_ERROR;

   return RETURN_OK;
}

/****** add_tab ****************************************************************
PROTO	int add_tab(tabstruct *tab, catstruct *cat, int pos)
PURPOSE	Add a table to a catalog.
INPUT	Pointer to the table,
	Pointer to the destination catalog,
	Position (1= first after the primary HDU, <=0 = at the end).
OUTPUT	RETURN_OK if everything went as expected, and RETURN_ERROR otherwise.
NOTES	Only 1-segment tables are accepted. To copy multi-segment tables,
	use copy_tab() instead.
	If a table with the same name and basic attributes already exists in
	the destination catalog, then the new table is appended to it.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	15/08/2003
 ***/
int	add_tab(tabstruct *tab, catstruct *cat, int pos)

  {
   tabstruct	*outtab, *prevtab;
   int		i;

/*Check if a similar table doesn't already exist in the dest. cat */
  if ((outtab = name_to_tab(cat, tab->extname, 0)))
    {
    if ((outtab->naxis != 2)
	|| (outtab->bitpix!=8)
	|| strcmp(outtab->xtension,tab->xtension)
	|| (outtab->tfields != tab->tfields)
        || (outtab->naxisn[0] != tab->naxisn[0]))
      return RETURN_ERROR;

    prevtab = outtab;
    for (i=outtab->nseg-1; i--;)
      prevtab = prevtab->nexttab;
    tab->seg = prevtab->seg+1;
    tab->nseg = 0;
    outtab->nseg++;
    }
  else
    {
    if ((prevtab = pos_to_tab(cat, pos, 0)))
      prevtab = prevtab->prevtab;
    else
      tab->nexttab = tab->prevtab = prevtab = tab;
    cat->ntab++;
    }

  (tab->nexttab = (tab->prevtab = prevtab)->nexttab)->prevtab = tab;
  prevtab->nexttab = tab;

  return RETURN_OK;
  }


/****** copy_tab **************************************************************
PROTO	int copy_tab(catstruct *catin, char *tabname, int seg,
		catstruct *catout, int pos)
PURPOSE	Copy a table from one catalog to another.
INPUT	Pointer to the original catalog,
	Name of the table,
	Table segment (0 = all),
	Pointer to the destination catalog,
	Position (1= first after the primary HDU, <=0 = at the end)
OUTPUT	RETURN_OK if everything went as expected, and RETURN_ERROR otherwise.
NOTES	If a table with the same name and basic attributes already exists in
	the destination catalog, then the original table is appended to it.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	15/08/2003
 ***/
int	copy_tab(catstruct *catin, char *tabname, int seg,
		catstruct *catout, int pos)

  {
   keystruct	*key;
   tabstruct	*outtab, *prevtab, *nexttab, *tabin,*tabout;
   int		i,j, nseg;

/*Convert the table name to a pointer*/
  if (!(tabin = name_to_tab(catin, tabname, seg)))
    return RETURN_ERROR;

  nseg = seg?1:tabin->nseg;
/*Check if a similar table doesn't already exist in the dest. cat */
  if (*tabname && (outtab = name_to_tab(catout, tabname, 0)))
    {
    if ((outtab->naxis != 2)
	|| (outtab->bitpix!=8)
	|| strcmp(outtab->xtension,tabin->xtension)
	|| (outtab->tfields != tabin->tfields)
        || (outtab->naxisn[0] != tabin->naxisn[0]))
      return RETURN_ERROR;
    prevtab = outtab;
    for (i=0; i<outtab->nseg-1; i++)
      prevtab = prevtab->nexttab;
    nexttab = prevtab->nexttab;
    outtab->nseg += nseg;
    }
  else
    {
    prevtab = nexttab = outtab = NULL;
    catout->ntab++;
    }

/*Now copy each segment of the original table*/
  tabout = NULL;	/* to satisfy gcc -Wall */
  for (i=nseg; i--;)
     {
/*---First, allocate memory and copy data */
     QCALLOC(tabout, tabstruct, 1);
     *tabout = *tabin;
     if (tabin->naxis)
       QMEMCPY(tabin->naxisn, tabout->naxisn, int, tabin->naxis);
     if (tabin->headbuf)
       QMEMCPY(tabin->headbuf, tabout->headbuf, char, tabin->headnblock*FBSIZE);
     if (tabin->bodybuf)
       QMEMCPY(tabin->bodybuf, tabout->bodybuf, char, tabin->tabsize);

     key = tabin->key;
     tabout->key = NULL;
     tabout->nkey = 0;
     for (j=tabin->nkey; j--;)
       {
       copy_key(tabin, key->name, tabout, 0);
       key = key->nextkey;
       }

/*---Then, update the links */
     if (prevtab)
       {
       prevtab->nexttab = tabout;
       tabout->prevtab = prevtab;
       tabout->seg = prevtab->seg+1;
       tabout->nseg = 0;
       }
     else
       {
       outtab = tabout;
       outtab->prevtab = NULL;
       tabout->seg = 1;
       }
     tabin = tabin->nexttab;
     prevtab = tabout;
     }

/*place the new chain of table-segments within the catalog (tricky, isn't it?)*/
  if (!nexttab)
/*--if the table is new */
    {
    nexttab = pos_to_tab(catout, pos, 0);
    if (!nexttab)
      nexttab = catout->tab = tabout;
    else
      {
      outtab->prevtab = nexttab->prevtab;
      nexttab->prevtab->nexttab = outtab;
      }
    }

  prevtab->nexttab = nexttab;
  nexttab->prevtab = prevtab;

  return RETURN_OK;
  }


/****** copy_tab_fromptr ******************************************************
PROTO	void copy_tab_fromptr(tabstruct *tabin, catstruct *catout, int pos)
PURPOSE	Copy a table from one catalog to another.
INPUT	Pointer to the original catalog,
	Pointer to the table,
	Pointer to the destination catalog,
	Position (1= first after the primary HDU, <=0 = at the end)
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	22/06/2001
 ***/
void	copy_tab_fromptr(tabstruct *tabin, catstruct *catout, int pos)

  {
   keystruct	*key;
   tabstruct	*prevtab, *nexttab,*tabout;
   int		j;

  catout->ntab++;

/* First, allocate memory and copy data */
   QCALLOC(tabout, tabstruct, 1);
   *tabout = *tabin;
   if (tabin->naxis)
     QMEMCPY(tabin->naxisn, tabout->naxisn, int, tabin->naxis);
   if (tabin->headbuf)
     QMEMCPY(tabin->headbuf, tabout->headbuf, char, tabin->headnblock*FBSIZE);
   if (tabin->bodybuf)
     QMEMCPY(tabin->bodybuf, tabout->bodybuf, char, tabin->tabsize);

   key = tabin->key;
   tabout->key = NULL;
   tabout->nkey = 0;
   for (j=tabin->nkey; j--;)
     {
     copy_key(tabin, key->name, tabout, 0);
     key = key->nextkey;
     }

/* Then, update the links */
   tabout->prevtab = NULL;
   tabout->seg = 1;
   tabin = tabin->nexttab;
   prevtab = tabout;

  if (!(nexttab = pos_to_tab(catout, pos, 0)))
    nexttab = catout->tab = tabout;
  else
    {
    tabout->prevtab = nexttab->prevtab;
    nexttab->prevtab->nexttab = tabout;
    }

  prevtab->nexttab = nexttab;
  nexttab->prevtab = prevtab;

  return;
  }


/****** copy_tabs **************************************************************
PROTO	int copy_tabs(catstruct *catin, catstruct *catout)
PURPOSE	Copy all tables from one catalog to another.
INPUT	Pointer to the original catalog,
	Pointer to the destination catalog,
OUTPUT	RETURN_OK if everything went as expected, and RETURN_ERROR otherwise
	(for instance if there were tabs that were not binary-tables, and
	therefore that were not copied).
NOTES	If a table with the same name and basic attributes already exists in
	the destination catalog, then the original table is appended to it.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	12/06/2001
 ***/
int	copy_tabs(catstruct *catin, catstruct *catout)

  {
   tabstruct	*tab;
   int		i, flag, ntab;

  if (!catin->tab)
    return RETURN_ERROR;

  tab = catin->tab->nexttab;	/* skip the primary header */
  flag = RETURN_OK;
  ntab = catin->ntab-1;
  if (!ntab)
    ntab = 1;
  for (i=ntab; i--;)
    {
    flag |= copy_tab(catin, tab->extname, 0, catout, 0);
    while (!(tab=tab->nexttab)->nseg);
    }

  return flag;
  }


/****** copy_tabs_blind *******************************************************
PROTO	int copy_tabs(catstruct *catin, catstruct *catout)
PURPOSE	Copy all tables from one catalog to another, without trying to append.
INPUT	Pointer to the original catalog,
	Pointer to the destination catalog,
OUTPUT	RETURN_OK if everything went as expected, and RETURN_ERROR otherwise.
NOTES	-.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	07/05/2002
 ***/
int	copy_tabs_blind(catstruct *catin, catstruct *catout)

  {
   tabstruct	*tab;
   int		i, ntab;

  if (!catin->tab)
    return RETURN_ERROR;

  tab = catin->tab;	/* don't skip the primary header */
  ntab = catin->ntab;
  for (i=ntab; i--;)
    {
    copy_tab_fromptr(tab, catout, 0);
    tab=tab->nexttab;
    }

  return RETURN_OK;
  }


/****** free_tab ***************************************************************
PROTO	void free_tab(tabstruct *tab)
PURPOSE	Free memory associated to a table pointer.
INPUT	Pointer to the table.
OUTPUT	-.
NOTES	-.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	28/02/2000
 ***/
void	free_tab(tabstruct *tab)

  {
  free_body(tab);
  free(tab->naxisn);
  free(tab->headbuf);
  free(tab->compress_buf);
  remove_keys(tab);
  free(tab);

  return;
  }


/****** new_tab ****************************************************************
PROTO	tabstruct *new_tab(char *tabname)
PURPOSE	Create a new binary table.
INPUT	Name.
OUTPUT	A pointer to the new table.
NOTES	A defaut header is also created.
	No links are initialized.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	25/04/97
 ***/
tabstruct	*new_tab(char *tabname)

  {
   static char	bintabtemplate[][80] = {
"XTENSION= 'BINTABLE'           / THIS IS A BINARY TABLE (FROM THE LDACTOOLS)",
"BITPIX  =                    8 / ",
"NAXIS   =                    2 / ",
"NAXIS1  =                    0 / BYTES PER ROW",
"NAXIS2  =                    0 / NUMBER OF ROWS",
"PCOUNT  =                    0 / RANDOM PARAMETER COUNT",
"GCOUNT  =                    1 / GROUP COUNT",
"TFIELDS =                    0 / FIELDS PER ROWS",
"EXTNAME = 'WHOCARES'           / TABLE NAME", 
"END                            "};
   tabstruct	*tab;
   char		*buf;
   int		i;

  QCALLOC(tab, tabstruct, 1);
  strcpy(tab->xtension, "BINTABLE");
  strcpy(tab->extname, tabname);
  tab->naxis = 2;
  QCALLOC(tab->naxisn, int, tab->naxis);
  tab->bitpix = 8;
  tab->bytepix = 1;
  tab->pcount = 0;
  tab->gcount = 1;
  tab->seg = 1;
  tab->nseg = 1;
/*Provide a new header*/
  QCALLOC(tab->headbuf, char, FBSIZE);
  memcpy(tab->headbuf, bintabtemplate, sizeof(bintabtemplate));
  for (buf = tab->headbuf, i=FBSIZE; i--; buf++)
    if (!*buf)
      *buf = ' ';
  tab->headnblock = 1;

  return tab;
  }


/****** remove_tab *************************************************************
PROTO	int remove_tab(catstruct *cat, char *tabname, int seg)
PURPOSE	Remove a table from a catalog.
INPUT	Pointer to the catalog,
	Name of the table,
	Table segment (0 = all).
OUTPUT	RETURN_OK if everything went as expected, and RETURN_ERROR otherwise.
NOTES	If tabname = "", the last table from the list is removed.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	15/08/2003
 ***/
int	remove_tab(catstruct *cat, char *tabname, int seg)

  {
   tabstruct	*tab, *prevtab, *nexttab;
   int		i,nseg;

  if (!tabname || !cat->ntab || !cat->tab)
    return RETURN_ERROR;

  if (tabname[0])
    {
/*--Convert the table name to a pointer*/
    if (!(tab = name_to_tab(cat, tabname, seg)))
      return RETURN_ERROR;
/*--a small trick to simplify decisions afterwards*/
    if (seg && tab->nseg==1)
      seg = 0;
    }
  else
    {
    tab = cat->tab->prevtab;
    if (!seg)
      for (;!tab->nseg; tab = tab->prevtab);
    }

  prevtab = tab->prevtab;
  nseg = seg?1:tab->nseg;

/*Free memory for each table segment*/
  nexttab = NULL;	/* to satisfy gcc -Wall */
  for (i=nseg; i--;)
    {
    nexttab = tab->nexttab;
    if (cat->tab == tab)
      cat->tab = nexttab;
    free_tab(tab);
    tab = nexttab;
    }

  if (!seg)
    if (!--cat->ntab)
      {
      cat->tab = NULL;
      return RETURN_OK;  
      }

/*update the links of neighbours*/
  nexttab->prevtab = prevtab;
  prevtab->nexttab = nexttab;

  if (seg)
/*--update status for each table segment*/
    {
    for (tab=prevtab;!tab->nseg; tab = tab->prevtab);
    for (nexttab=tab->nexttab,i=2;!nexttab->nseg;nexttab=nexttab->nexttab,i++);
      nexttab->seg = i;
    tab->nseg = i;
    tab->seg = 1;
    }

  return RETURN_OK;  
  }


/****** remove_tabs ************************************************************
PROTO	int remove_tabs(catstruct *cat)
PURPOSE	Remove all tables from a catalog.
INPUT	Pointer to the catalog.
OUTPUT	RETURN_OK if tabs were found, and RETURN_ERROR otherwise.
NOTES	-.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	25/05/97
 ***/
int	remove_tabs(catstruct *cat)

  {
   int	t;

  if (!cat->tab)
    return RETURN_ERROR;

  for (t=cat->ntab; t--;)
    remove_tab(cat, "",0);

  return RETURN_OK;
  }


/****** update_tab ************************************************************
PROTO	int update_tab(tabstruct *tab)
PURPOSE	Update a table according to what's in the keys.
INPUT	Table structure.
OUTPUT	RETURN_OK if tab is a binary table, or RETURN_ERROR otherwise.
NOTES	The headbuf pointer in the catstruct might be reallocated.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	08/02/97
 ***/
int	update_tab(tabstruct *tab)

  {
   tabstruct	*keytab;
   keystruct	*key;
   int		i,j, nobj, nbytes;

/*Just pass if not a binary table*/
  if ((tab->naxis != 2)
	|| (tab->bitpix!=8)
	|| strncmp(tab->xtension, "BINTABLE", 8))
    return RETURN_ERROR;

/*Well, not much to do if there are no keys!*/
  if (!(key = tab->key))
    return RETURN_OK;

  nobj = -1;
  keytab = NULL;
  nbytes = 0;
  for (i=tab->nkey; i--;)
    {
    if (keytab && !key->ptr && key->tab != keytab)
      error(EXIT_FAILURE, "*Error*: wrong reference table in ",
	key->name);
    if (nobj!=-1 && (nobj != key->nobj))
      error(EXIT_FAILURE, "*Error*: wrong number of elements in key ",
	key->name);
    keytab = key->tab;
    nobj = key->nobj;
/*-- If the number of bytes per element is not set, recover it */
    if (!key->nbytes)
      {
      key->nbytes = t_size[key->ttype];
      for (j=key->naxis; j--;)
        key->nbytes *= key->naxisn[j];
      }
    nbytes += key->nbytes;
    key = key->nextkey;
    }

  tab->tabsize = nobj*nbytes;
  tab->naxisn[0] = nbytes;
  tab->naxisn[1] = nobj;
  tab->tfields = tab->nkey;

  return RETURN_OK;
  }


/****** name_to_tab ***********************************************************
PROTO	tabstruct *name_to_tab(catstruct *cat, char *tabname, int seg)
PURPOSE	Name search of a table in a catalog.
INPUT	Pointer to the catalog,
	Table name,
	Table segment (0 = first).
OUTPUT	The table pointer if the name was matched, and NULL otherwise.
NOTES	-
VERSION	12/06/2001
 ***/
tabstruct	*name_to_tab(catstruct *cat, char *tabname, int seg)

  {
   tabstruct	*tab;
   int		i;

  if (!(tab = cat->tab))
    return NULL;

  for (i=cat->ntab; strcmp(tabname,tab->extname) && i--;)
    while (!(tab=tab->nexttab)->nseg);

  if (i<0)
    return NULL;

  if (seg)
    {
    for (;tab->seg!=seg && !tab->nexttab->nseg; tab=tab->nexttab);
    return tab->seg==seg?tab:NULL;
    }

  return tab;
  }


/****** pos_to_tab *************************************************************
PROTO	tabstruct *pos_to_tab(catstruct *cat, int pos, int seg)
PURPOSE	Position search of a table in a catalog.
INPUT	Pointer to the catalog,
	Position of the table,
	Table segment (0 = first).
OUTPUT	The table pointer if the table exists at the given position, and the
	pointer to the primary ``table'' otherwise.
NOTES	pos = 1 means the first table after the primary one.
AUTHOR	E. Bertin (IAP & Leiden observatory)
VERSION	15/02/96
 ***/
tabstruct	*pos_to_tab(catstruct *cat, int pos, int seg)

  {
   tabstruct	*tab;
   int		i;

  tab = cat->tab;
  for (i=0; i!=pos && i<cat->ntab; i++)
    while (!(tab=tab->nexttab)->nseg);

  if (seg)
    for (;tab->seg!=seg && !tab->nexttab->nseg; tab=tab->nexttab);

  return i<cat->ntab?tab:cat->tab;
  }

/****** tabs_list **************************************************************
PROTO	char **tabs_list(catstruct *cat, int *n)
PURPOSE	List all tables in a catalog.
INPUT	Pointer to the catalog,
	Pointer to the number of names in that list.
OUTPUT	A list of all table names.
NOTES	-.
AUTHOR	E.R. Deul (Leiden observatory)
VERSION	??/??/96
 ***/
char **tabs_list(catstruct *cat, int *n)

  {
   tabstruct	*tab;
   int		i;
   char 	**names;

  tab = cat->tab;
  QCALLOC(names, char *, cat->ntab);
  for (i=0; i<cat->ntab; i++) {
    QCALLOC(names[i], char, MAXCHARS);
    strcpy(names[i],tab->extname);
    while (!(tab=tab->nexttab)->nseg);
  }
  *n = cat->ntab;
  return names;
  }

/****** tabs_row_len ***********************************************************
PROTO	int tab_row_len(char *file, char *tabname)
PURPOSE	Return the row length in bytes of a given table in a given catalog.
INPUT	File pointer.
OUTPUT	Table size (bytes)
NOTES	-.
AUTHOR	E.R. Deul (Leiden observatory)
VERSION	05/06/200`
 ***/
int tab_row_len(char *file, char *tabname)

{
    catstruct   *tcat;
    tabstruct   *tab;
    int		retcode = -1;

    if ((tcat = read_cat(file)) != NULL) {
       if ((tab = name_to_tab(tcat, tabname, 0)) != NULL) {
          retcode = tab->naxisn[0];
	  free_tab(tab);
       }
       close_cat(tcat);
       free_cat(&tcat,1);
    }
    return retcode;
}