summaryrefslogtreecommitdiff
path: root/strings/my_vsnprintf.c
blob: 4178b20789dcd6c43aadc2cc1e84571535c3e97d (plain)
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
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
/* Copyright (c) 2000, 2011, Oracle and/or its affiliates.
   Copyright (c) 2009-2011, Monty Program Ab

   This program 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; version 2 of the License.

   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA */

#include "strings_def.h"
#include <m_ctype.h>
#include <stdarg.h>
#include <my_sys.h>
#include <my_base.h>
#include <my_handler_errors.h>


#define MAX_ARGS 32                           /* max positional args count*/
#define MAX_PRINT_INFO 32                     /* max print position count */
#define MAX_WIDTH      65535

#define LENGTH_ARG     1
#define WIDTH_ARG      2
#define PREZERO_ARG    4
#define ESCAPED_ARG    8 

typedef struct pos_arg_info ARGS_INFO;
typedef struct print_info PRINT_INFO;

struct pos_arg_info
{
  char arg_type;                              /* argument type */
  uint have_longlong;                         /* used from integer values */
  char *str_arg;                              /* string value of the arg */
  longlong longlong_arg;                      /* integer value of the arg */
  double double_arg;                          /* double value of the arg */
};


struct print_info
{
  char arg_type;                              /* argument type */
  size_t arg_idx;                             /* index of the positional arg */
  size_t length;                              /* print width or arg index */
  size_t width;                               /* print width or arg index */
  uint flags;
  const char *begin;                          /**/
  const char *end;                            /**/
};


/**
  Calculates print length or index of positional argument

  @param fmt         processed string
  @param length      print length or index of positional argument
  @param pre_zero    returns flags with PREZERO_ARG set if necessary

  @retval
    string position right after length digits
*/

static const char *get_length(const char *fmt, size_t *length, uint *pre_zero)
{
  
  for (; my_isdigit(&my_charset_latin1, *fmt); fmt++)
  {
    *length= *length * 10 + (uint)(*fmt - '0');
    if (!*length)
      *pre_zero|= PREZERO_ARG;                  /* first digit was 0 */
  }
  return fmt;
}


/*
  Get argument for '*' parameter

  @param fmt         processed string
  @param args_arr    Arguments to printf
  @param arg_count   Number of arguments to printf
  @param length      returns length of argument
  @param flag        returns flags with PREZERO_ARG set if necessary

  @return new fmt
*/

static const char *get_length_arg(const char *fmt, ARGS_INFO *args_arr,
                                  uint *arg_count, size_t *length, uint *flags)
{
  fmt= get_length(fmt+1, length, flags);
  *arg_count= MY_MAX(*arg_count, (uint) *length);
  (*length)--;    
  DBUG_ASSERT(*fmt == '$' && *length < MAX_ARGS);
  args_arr[*length].arg_type= 'd';
  args_arr[*length].have_longlong= 0;
  return fmt+1;
}

/**
  Calculates print width or index of positional argument

  @param fmt            processed string
  @param have_longlong  TRUE if longlong is required

  @retval
    string position right after modifier symbol
*/

static const char *check_longlong(const char *fmt, uint *have_longlong)
{
  *have_longlong= 0;
  if (*fmt == 'l')
  {
    fmt++;
    if (*fmt != 'l')
      *have_longlong= (sizeof(long) == sizeof(longlong));
    else
    {
      fmt++;
      *have_longlong= 1;
    }
  }
  else if (*fmt == 'z')
  {
    fmt++;
    *have_longlong= (sizeof(size_t) == sizeof(longlong));
  }
  else if (*fmt == 'p')
    *have_longlong= (sizeof(void *) == sizeof(longlong));
  return fmt;
}


/**
  Returns escaped string

  @param cs         string charset
  @param to         buffer where escaped string will be placed
  @param end        end of buffer
  @param par        string to escape
  @param par_len    string length
  @param quote_char character for quoting

  @retval
    position in buffer which points on the end of escaped string
*/

static char *backtick_string(CHARSET_INFO *cs, char *to, const char *end,
                             char *par, size_t par_len, char quote_char)
{
  uint char_len;
  char *start= to;
  char *par_end= par + par_len;
  size_t buff_length= (size_t) (end - to);

  if (buff_length <= par_len)
    goto err;
  *start++= quote_char;

  for ( ; par < par_end; par+= char_len)
  {
    uchar c= *(uchar *) par;
    if (!(char_len= my_mbcharlen(cs, c)))
      char_len= 1;
    if (char_len == 1 && c == (uchar) quote_char )
    {
      if (start + 1 >= end)
        goto err;
      *start++= quote_char;
    }
    if (start + char_len >= end)
      goto err;
    start= strnmov(start, par, char_len);
  }
    
  if (start + 1 >= end)
    goto err;
  *start++= quote_char;
  return start;

err:
    *to='\0';
  return to;
}


/**
  Prints string argument
*/

static char *process_str_arg(CHARSET_INFO *cs, char *to, const char *end,
                             size_t width, char *par, uint print_type)
{
  int well_formed_error;
  size_t plen, left_len= (size_t) (end - to) + 1;
  if (!par)
    par = (char*) "(null)";

  plen= strnlen(par, width);
  if (left_len <= plen)
    plen = left_len - 1;
  plen= cs->cset->well_formed_len(cs, par, par + plen,
                                  width, &well_formed_error);
  if (print_type & ESCAPED_ARG)
    to= backtick_string(cs, to, end, par, plen, '`');
  else
    to= strnmov(to,par,plen);
  return to;
}


/**
  Prints binary argument
*/

static char *process_bin_arg(char *to, char *end, size_t width, char *par)
{
  DBUG_ASSERT(to <= end);
  if (to + width + 1 > end)
    width= end - to - 1;  /* sign doesn't matter */
  memmove(to, par, width);
  to+= width;
  return to;
}


/**
  Prints double or float argument
*/

static char *process_dbl_arg(char *to, char *end, size_t width,
                             double par, char arg_type)
{
  if (width == MAX_WIDTH)
    width= FLT_DIG; /* width not set, use default */
  else if (width >= NOT_FIXED_DEC)
    width= NOT_FIXED_DEC - 1; /* max.precision for my_fcvt() */
  width= MY_MIN(width, (size_t)(end-to) - 1);
  
  if (arg_type == 'f')
    to+= my_fcvt(par, (int)width , to, NULL);
  else
    to+= my_gcvt(par, MY_GCVT_ARG_DOUBLE, (int) width , to, NULL);
  return to;
}


/**
  Prints integer argument
*/

static char *process_int_arg(char *to, const char *end, size_t length,
                             longlong par, char arg_type, uint print_type)
{
  size_t res_length, to_length;
  char *store_start= to, *store_end;
  char buff[32];

  if ((to_length= (size_t) (end-to)) < 16 || length)
    store_start= buff;

  if (arg_type == 'd' || arg_type == 'i')
    store_end= longlong10_to_str(par, store_start, -10);
  else if (arg_type == 'u')
    store_end= longlong10_to_str(par, store_start, 10);
  else if (arg_type == 'p')
  {
    store_start[0]= '0';
    store_start[1]= 'x';
    store_end= ll2str(par, store_start + 2, 16, 0);
  }
  else if (arg_type == 'o')
  {
    store_end= ll2str(par, store_start, 8, 0);
  }
  else
  {
    DBUG_ASSERT(arg_type == 'X' || arg_type =='x');
    store_end= ll2str(par, store_start, 16, (arg_type == 'X'));
  }

  if ((res_length= (size_t) (store_end - store_start)) > to_length)
    return to;                           /* num doesn't fit in output */
  /* If %#d syntax was used, we have to pre-zero/pre-space the string */
  if (store_start == buff)
  {
    length= MY_MIN(length, to_length);
    if (res_length < length)
    {
      size_t diff= (length- res_length);
      bfill(to, diff, (print_type & PREZERO_ARG) ? '0' : ' ');
      if (arg_type == 'p' && print_type & PREZERO_ARG)
      {
        if (diff > 1)
          to[1]= 'x';
        else
          store_start[0]= 'x';
        store_start[1]= '0';
      }
      to+= diff;
    }
    bmove(to, store_start, res_length);
  }
  to+= res_length;
  return to;
}


/**
  Procesed positional arguments.

  @param cs         string charset
  @param to         buffer where processed string will be place
  @param end        end of buffer
  @param par        format string
  @param arg_index  arg index of the first occurrence of positional arg
  @param ap         list of parameters

  @retval
    end of buffer where processed string is placed
*/

static char *process_args(CHARSET_INFO *cs, char *to, char *end,
                          const char* fmt, size_t arg_index, va_list ap)
{
  ARGS_INFO args_arr[MAX_ARGS];
  PRINT_INFO print_arr[MAX_PRINT_INFO];
  uint idx= 0, arg_count= arg_index;

start:
  /* Here we are at the beginning of positional argument, right after $ */
  arg_index--;
  print_arr[idx].flags= 0;
  if (*fmt == '`')
  {
    print_arr[idx].flags|= ESCAPED_ARG;
    fmt++;
  }
  if (*fmt == '-')
    fmt++;
  print_arr[idx].length= print_arr[idx].width= 0;
  /* Get print length */
  if (*fmt == '*')
  {          
    fmt= get_length_arg(fmt, args_arr, &arg_count, &print_arr[idx].length,
                        &print_arr[idx].flags);
    print_arr[idx].flags|= LENGTH_ARG;
  }
  else
    fmt= get_length(fmt, &print_arr[idx].length, &print_arr[idx].flags);
  
  if (*fmt == '.')
  {
    uint unused_flags= 0;
    fmt++;
    /* Get print width */
    if (*fmt == '*')
    {
      fmt= get_length_arg(fmt, args_arr, &arg_count, &print_arr[idx].width,
                          &unused_flags);
      print_arr[idx].flags|= WIDTH_ARG;
    }
    else
      fmt= get_length(fmt, &print_arr[idx].width, &unused_flags);
  }
  else
    print_arr[idx].width= MAX_WIDTH;

  fmt= check_longlong(fmt, &args_arr[arg_index].have_longlong);
  args_arr[arg_index].arg_type= print_arr[idx].arg_type= *fmt;
  
  print_arr[idx].arg_idx= arg_index;
  print_arr[idx].begin= ++fmt;

  while (*fmt && *fmt != '%')
    fmt++;

  if (!*fmt)                                  /* End of format string */
  {
    uint i;
    print_arr[idx].end= fmt;
    /* Obtain parameters from the list */
    for (i= 0 ; i < arg_count; i++)
    {
      switch (args_arr[i].arg_type) {
      case 's':
      case 'b':
        args_arr[i].str_arg= va_arg(ap, char *);
        break;
      case 'f':
      case 'g':
        args_arr[i].double_arg= va_arg(ap, double);
        break;
      case 'd':
      case 'i':
      case 'u':
      case 'x':
      case 'X':
      case 'o':
      case 'p':
        if (args_arr[i].have_longlong)
          args_arr[i].longlong_arg= va_arg(ap,longlong);
        else if (args_arr[i].arg_type == 'd' || args_arr[i].arg_type == 'i')
          args_arr[i].longlong_arg= va_arg(ap, int);
        else
          args_arr[i].longlong_arg= va_arg(ap, uint);
        break;
      case 'M':
      case 'c':
        args_arr[i].longlong_arg= va_arg(ap, int);
        break;
      default:
        DBUG_ASSERT(0);
      }
    }
    /* Print result string */
    for (i= 0; i <= idx; i++)
    {
      size_t width= 0, length= 0;
      switch (print_arr[i].arg_type) {
      case 's':
      {
        char *par= args_arr[print_arr[i].arg_idx].str_arg;
        width= (print_arr[i].flags & WIDTH_ARG)
          ? (size_t)args_arr[print_arr[i].width].longlong_arg
          : print_arr[i].width;
        to= process_str_arg(cs, to, end, width, par, print_arr[i].flags);
        break;
      }
      case 'b':
      {
        char *par = args_arr[print_arr[i].arg_idx].str_arg;
        width= (print_arr[i].flags & WIDTH_ARG)
          ? (size_t)args_arr[print_arr[i].width].longlong_arg
          : print_arr[i].width;
        to= process_bin_arg(to, end, width, par);
        break;
      }
      case 'c':
      {
        if (to == end)
          break;
        *to++= (char) args_arr[print_arr[i].arg_idx].longlong_arg;
        break;
      }
      case 'f':
      case 'g':
      {
        double d= args_arr[print_arr[i].arg_idx].double_arg;
        width= (print_arr[i].flags & WIDTH_ARG) ?
          (uint)args_arr[print_arr[i].width].longlong_arg : print_arr[i].width;
        to= process_dbl_arg(to, end, width, d, print_arr[i].arg_type);
        break;
      }
      case 'd':
      case 'i':
      case 'u':
      case 'x':
      case 'X':
      case 'o':
      case 'p':
      {
        /* Integer parameter */
        longlong larg;
        length= (print_arr[i].flags & LENGTH_ARG)
          ? (size_t)args_arr[print_arr[i].length].longlong_arg
          : print_arr[i].length;

        larg = args_arr[print_arr[i].arg_idx].longlong_arg;
        to= process_int_arg(to, end, length, larg, print_arr[i].arg_type,
                            print_arr[i].flags);
        break;
      }
      case 'M':
      {
        longlong larg;
        const char *real_end;

        width= (print_arr[i].flags & WIDTH_ARG)
          ? (size_t)args_arr[print_arr[i].width].longlong_arg
          : print_arr[i].width;

        real_end= MY_MIN(to + width, end);

        larg = args_arr[print_arr[i].arg_idx].longlong_arg;
        to= process_int_arg(to, real_end, 0, larg, 'd', print_arr[i].flags);
        if (real_end - to >= 3)
        {
          char errmsg_buff[MYSYS_STRERROR_SIZE];
          *to++= ' ';
          *to++= '"';
          my_strerror(errmsg_buff, sizeof(errmsg_buff), larg);
          to= process_str_arg(cs, to, real_end, width, errmsg_buff,
                              print_arr[i].flags);
          if (real_end > to) *to++= '"';
        }
        break;
      }
      default:
        break;
      }

      if (to == end)
        break;

      /* Copy data after the % format expression until next % */
      length= MY_MIN(end - to , print_arr[i].end - print_arr[i].begin);
      if (to + length < end)
        length++;
      to= strnmov(to, print_arr[i].begin, length);
    }
    DBUG_ASSERT(to <= end);
    *to='\0';				/* End of errmessage */
    return to;
  }
  else
  {
    uint unused_flags= 0;
    /* Process next positional argument*/
    DBUG_ASSERT(*fmt == '%');
    print_arr[idx].end= fmt - 1;
    idx++;
    fmt++;
    arg_index= 0;
    fmt= get_length(fmt, &arg_index, &unused_flags);
    DBUG_ASSERT(*fmt == '$');
    fmt++;
    arg_count= MY_MAX(arg_count, arg_index);
    goto start;
  }

  return 0;
}



/**
  Produces output string according to a format string

  See the detailed documentation around my_snprintf_service_st

  @param cs         string charset
  @param to         buffer where processed string will be place
  @param n          size of buffer
  @param par        format string
  @param ap         list of parameters

  @retval
    length of result string
*/

size_t my_vsnprintf_ex(CHARSET_INFO *cs, char *to, size_t n,
                       const char* fmt, va_list ap)
{
  char *start=to, *end=to+n-1;
  size_t length, width;
  uint print_type, have_longlong;

  for (; *fmt ; fmt++)
  {
    if (*fmt != '%')
    {
      if (to == end)                            /* End of buffer */
	break;
      *to++= *fmt;                            /* Copy ordinary char */
      continue;
    }
    fmt++;					/* skip '%' */

    length= width= 0;
    print_type= 0;

    /* Read max fill size (only used with %d and %u) */
    if (my_isdigit(&my_charset_latin1, *fmt))
    {
      fmt= get_length(fmt, &length, &print_type);
      if (*fmt == '$')
      {
        to= process_args(cs, to, end, (fmt+1), length, ap);
        return (size_t) (to - start);
      }
    }
    else
    {
      if (*fmt == '`')
      {
        print_type|= ESCAPED_ARG;
        fmt++;
      }
      if (*fmt == '-')
        fmt++;
      if (*fmt == '*')
      {
        fmt++;
        length= va_arg(ap, int);
      }
      else
        fmt= get_length(fmt, &length, &print_type);
    }

    if (*fmt == '.')
    {
      uint unused_flags= 0;
      fmt++;
      if (*fmt == '*')
      {
        fmt++;
        width= va_arg(ap, int);
      }
      else
        fmt= get_length(fmt, &width, &unused_flags);
    }
    else
      width= MAX_WIDTH;

    fmt= check_longlong(fmt, &have_longlong);

    if (*fmt == 's')				/* String parameter */
    {
      reg2 char *par= va_arg(ap, char *);
      to= process_str_arg(cs, to, end, width, par, print_type);
      continue;
    }
    else if (*fmt == 'b')				/* Buffer parameter */
    {
      char *par = va_arg(ap, char *);
      to= process_bin_arg(to, end, width, par);
      continue;
    }
    else if (*fmt == 'f' || *fmt == 'g')
    {
      double d= va_arg(ap, double);
      to= process_dbl_arg(to, end, width, d, *fmt);
      continue;
    }
    else if (*fmt == 'd' || *fmt == 'i' || *fmt == 'u' || *fmt == 'x' || 
             *fmt == 'X' || *fmt == 'p' || *fmt == 'o')
    {
      /* Integer parameter */
      longlong larg;

      if (have_longlong)
        larg = va_arg(ap,longlong);
      else if (*fmt == 'd' || *fmt == 'i')
        larg = va_arg(ap, int);
      else
        larg= va_arg(ap, uint);

      to= process_int_arg(to, end, length, larg, *fmt, print_type);
      continue;
    }
    else if (*fmt == 'c')                       /* Character parameter */
    {
      register int larg;
      if (to == end)
        break;
      larg = va_arg(ap, int);
      *to++= (char) larg;
      continue;
    }
    else if (*fmt == 'M')
    {
      int larg= va_arg(ap, int);
      const char *real_end= MY_MIN(to + width, end);

      to= process_int_arg(to, real_end, 0, larg, 'd', print_type);
      if (real_end - to >= 3)
      {
        char errmsg_buff[MYSYS_STRERROR_SIZE];
        *to++= ' ';
        *to++= '"';
        my_strerror(errmsg_buff, sizeof(errmsg_buff), larg);
        to= process_str_arg(cs, to, real_end, width, errmsg_buff, print_type);
        if (real_end > to) *to++= '"';
      }
      continue;
    }

    /* We come here on '%%', unknown code or too long parameter */
    if (to >= end)
      break;
    *to++='%';				/* % used as % or unknown code */
  }
  DBUG_ASSERT(to <= end);
  *to='\0';				/* End of errmessage */
  return (size_t) (to - start);
}


/*
  Limited snprintf() implementations

  exported to plugins as a service, see the detailed documentation
  around my_snprintf_service_st
*/

size_t my_vsnprintf(char *to, size_t n, const char* fmt, va_list ap)
{
  return my_vsnprintf_ex(&my_charset_latin1, to, n, fmt, ap);
}


size_t my_snprintf(char* to, size_t n, const char* fmt, ...)
{
  size_t result;
  va_list args;
  va_start(args,fmt);
  result= my_vsnprintf(to, n, fmt, args);
  va_end(args);
  return result;
}


/**
  Writes output to the stream according to a format string.

  @param stream     file to write to
  @param format     string format
  @param args       list of parameters

  @retval
    number of the characters written.
*/

int my_vfprintf(FILE *stream, const char* format, va_list args)
{
  char cvtbuf[1024];
  int alloc= 0;
  char *p= cvtbuf;
  size_t cur_len= sizeof(cvtbuf), actual;
  int ret;

  /*
    We do not know how much buffer we need.
    So start with a reasonably-sized stack-allocated buffer, and increase
    it exponentially until it is big enough.
  */
  for (;;)
  {
    size_t new_len;
    actual= my_vsnprintf(p, cur_len, format, args);
    if (actual < cur_len - 1)
      break;
    /*
      Not enough space (or just enough with nothing to spare - but we cannot
      distinguish this case from the return value). Allocate a bigger buffer
      and try again.
    */
    if (alloc)
      (*my_str_free)(p);
    else
      alloc= 1;
    new_len= cur_len*2;
    if (new_len < cur_len)
      return 0;                                 /* Overflow */
    cur_len= new_len;
    p= (*my_str_malloc)(cur_len);
    if (!p)
      return 0;
  }
  ret= (int) actual;
  if (fputs(p, stream) < 0)
    ret= -1;
  if (alloc)
    (*my_str_free)(p);
  return ret;
}

int my_fprintf(FILE *stream, const char* format, ...)
{
  int result;
  va_list args;
  va_start(args, format);
  result= my_vfprintf(stream, format, args);
  va_end(args);
  return result;
}


/*
  Return system error text for given error number

  @param buf        Buffer (of size MYSYS_STRERROR_SIZE)
  @param len        Length of buffer
  @param nr         Error number
*/

void my_strerror(char *buf, size_t len, int nr)
{
  char *msg= NULL;

  buf[0]= '\0';                                  /* failsafe */

  if (nr <= 0)
  {
    strmake(buf, (nr == 0 ?
                  "Internal error/check (Not system error)" :
                  "Internal error < 0 (Not system error)"),
            len-1);
    return;
  }

  /*
    These (handler-) error messages are shared by perror, as required
    by the principle of least surprise.
  */
  if ((nr >= HA_ERR_FIRST) && (nr <= HA_ERR_LAST))
  {
    msg= (char *) handler_error_messages[nr - HA_ERR_FIRST];
    strmake(buf, msg, len - 1);
  }
  else
  {
    /*
      On Windows, do things the Windows way. On a system that supports both
      the GNU and the XSI variant, use whichever was configured (GNU); if
      this choice is not advertised, use the default (POSIX/XSI).  Testing
      for __GNUC__ is not sufficient to determine whether this choice exists.
    */
#if defined(__WIN__)
    strerror_s(buf, len, nr);
#elif ((defined _POSIX_C_SOURCE && (_POSIX_C_SOURCE >= 200112L)) ||    \
       (defined _XOPEN_SOURCE   && (_XOPEN_SOURCE >= 600)))      &&    \
      ! defined _GNU_SOURCE
    strerror_r(nr, buf, len);             /* I can build with or without GNU */
#elif defined(__GLIBC__) && defined (_GNU_SOURCE)
    char *r= strerror_r(nr, buf, len);
    if (r != buf)                         /* Want to help, GNU? */
      strmake(buf, r, len - 1);           /* Then don't. */
#else
    strerror_r(nr, buf, len);
#endif
  }

  /*
    strerror() return values are implementation-dependent, so let's
    be pragmatic.
  */
  if (!buf[0])
    strmake(buf, "unknown error", len - 1);
}