summaryrefslogtreecommitdiff
path: root/sprintf.c
blob: becc25b2d22905bd39534a56cc1176158583ae79 (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
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
/**********************************************************************

  sprintf.c -

  $Author$
  created at: Fri Oct 15 10:39:26 JST 1993

  Copyright (C) 1993-2007 Yukihiro Matsumoto
  Copyright (C) 2000  Network Applied Communication Laboratory, Inc.
  Copyright (C) 2000  Information-technology Promotion Agency, Japan

**********************************************************************/

#include "ruby/ruby.h"
#include "ruby/re.h"
#include "ruby/encoding.h"
#include <math.h>
#include <stdarg.h>

#ifdef HAVE_IEEEFP_H
#include <ieeefp.h>
#endif

#define BIT_DIGITS(N)   (((N)*146)/485 + 1)  /* log2(10) =~ 146/485 */
#define BITSPERDIG (SIZEOF_BDIGITS*CHAR_BIT)
#define EXTENDSIGN(n, l) (((~0 << (n)) >> (((n)*(l)) % BITSPERDIG)) & ~(~0 << (n)))

static void fmt_setup(char*,size_t,int,int,int,int);

static char*
remove_sign_bits(char *str, int base)
{
    char *t = str;

    if (base == 16) {
	while (*t == 'f') {
	    t++;
	}
    }
    else if (base == 8) {
	*t |= EXTENDSIGN(3, strlen(t));
	while (*t == '7') {
	    t++;
	}
    }
    else if (base == 2) {
	while (*t == '1') {
	    t++;
	}
    }

    return t;
}

static char
sign_bits(int base, const char *p)
{
    char c = '.';

    switch (base) {
      case 16:
	if (*p == 'X') c = 'F';
	else c = 'f';
	break;
      case 8:
	c = '7'; break;
      case 2:
	c = '1'; break;
    }
    return c;
}

#define FNONE  0
#define FSHARP 1
#define FMINUS 2
#define FPLUS  4
#define FZERO  8
#define FSPACE 16
#define FWIDTH 32
#define FPREC  64
#define FPREC0 128

#define CHECK(l) do {\
    int cr = ENC_CODERANGE(result);\
    while (blen + (l) >= bsiz) {\
	bsiz*=2;\
    }\
    rb_str_resize(result, bsiz);\
    ENC_CODERANGE_SET(result, cr);\
    buf = RSTRING_PTR(result);\
} while (0)

#define PUSH(s, l) do { \
    CHECK(l);\
    memcpy(&buf[blen], (s), (l));\
    blen += (l);\
} while (0)

#define FILL(c, l) do { \
    CHECK(l);\
    memset(&buf[blen], (c), (l));\
    blen += (l);\
} while (0)

#define GETARG() (nextvalue != Qundef ? nextvalue : \
    posarg == -1 ? \
    (rb_raise(rb_eArgError, "unnumbered(%d) mixed with numbered", nextarg), 0) : \
    posarg == -2 ? \
    (rb_raise(rb_eArgError, "unnumbered(%d) mixed with named", nextarg), 0) : \
    (posarg = nextarg++, GETNTHARG(posarg)))

#define GETPOSARG(n) (posarg > 0 ? \
    (rb_raise(rb_eArgError, "numbered(%d) after unnumbered(%d)", (n), posarg), 0) : \
    posarg == -2 ? \
    (rb_raise(rb_eArgError, "numbered(%d) after named", (n)), 0) : \
    (((n) < 1) ? (rb_raise(rb_eArgError, "invalid index - %d$", (n)), 0) : \
	       (posarg = -1, GETNTHARG(n))))

#define GETNTHARG(nth) \
    (((nth) >= argc) ? (rb_raise(rb_eArgError, "too few arguments"), 0) : argv[(nth)])

#define GETNAMEARG(id, name, len) ( \
    posarg > 0 ? \
    (rb_raise(rb_eArgError, "named%.*s after unnumbered(%d)", (len), (name), posarg), 0) : \
    posarg == -1 ? \
    (rb_raise(rb_eArgError, "named%.*s after numbered", (len), (name)), 0) :	\
    (posarg = -2, rb_hash_lookup2(get_hash(&hash, argc, argv), (id), Qundef)))

#define GETNUM(n, val) \
    for (; p < end && rb_enc_isdigit(*p, enc); p++) {	\
	int next_n = 10 * (n) + (*p - '0'); \
        if (next_n / 10 != (n)) {\
	    rb_raise(rb_eArgError, #val " too big"); \
	} \
	(n) = next_n; \
    } \
    if (p >= end) { \
	rb_raise(rb_eArgError, "malformed format string - %%*[0-9]"); \
    }

#define GETASTER(val) do { \
    t = p++; \
    n = 0; \
    GETNUM(n, (val)); \
    if (*p == '$') { \
	tmp = GETPOSARG(n); \
    } \
    else { \
	tmp = GETARG(); \
	p = t; \
    } \
    (val) = NUM2INT(tmp); \
} while (0)

static VALUE
get_hash(volatile VALUE *hash, int argc, const VALUE *argv)
{
    VALUE tmp;

    if (*hash != Qundef) return *hash;
    if (argc != 2) {
	rb_raise(rb_eArgError, "one hash required");
    }
    tmp = rb_check_convert_type(argv[1], T_HASH, "Hash", "to_hash");
    if (NIL_P(tmp)) {
	rb_raise(rb_eArgError, "one hash required");
    }
    return (*hash = tmp);
}

/*
 *  call-seq:
 *     format(format_string [, arguments...] )   -> string
 *     sprintf(format_string [, arguments...] )  -> string
 *
 *  Returns the string resulting from applying <i>format_string</i> to
 *  any additional arguments.  Within the format string, any characters
 *  other than format sequences are copied to the result.
 *
 *  The syntax of a format sequence is follows.
 *
 *    %[flags][width][.precision]type
 *
 *  A format
 *  sequence consists of a percent sign, followed by optional flags,
 *  width, and precision indicators, then terminated with a field type
 *  character.  The field type controls how the corresponding
 *  <code>sprintf</code> argument is to be interpreted, while the flags
 *  modify that interpretation.
 *
 *  The field type characters are:
 *
 *      Field |  Integer Format
 *      ------+--------------------------------------------------------------
 *        b   | Convert argument as a binary number.
 *            | Negative numbers will be displayed as a two's complement
 *            | prefixed with `..1'.
 *        B   | Equivalent to `b', but uses an uppercase 0B for prefix
 *            | in the alternative format by #.
 *        d   | Convert argument as a decimal number.
 *        i   | Identical to `d'.
 *        o   | Convert argument as an octal number.
 *            | Negative numbers will be displayed as a two's complement
 *            | prefixed with `..7'.
 *        u   | Identical to `d'.
 *        x   | Convert argument as a hexadecimal number.
 *            | Negative numbers will be displayed as a two's complement
 *            | prefixed with `..f' (representing an infinite string of
 *            | leading 'ff's).
 *        X   | Equivalent to `x', but uses uppercase letters.
 *
 *      Field |  Float Format
 *      ------+--------------------------------------------------------------
 *        e   | Convert floating point argument into exponential notation
 *            | with one digit before the decimal point as [-]d.dddddde[+-]dd.
 *            | The precision specifies the number of digits after the decimal
 *            | point (defaulting to six).
 *        E   | Equivalent to `e', but uses an uppercase E to indicate
 *            | the exponent.
 *        f   | Convert floating point argument as [-]ddd.dddddd,
 *            | where the precision specifies the number of digits after
 *            | the decimal point.
 *        g   | Convert a floating point number using exponential form
 *            | if the exponent is less than -4 or greater than or
 *            | equal to the precision, or in dd.dddd form otherwise.
 *            | The precision specifies the number of significant digits.
 *        G   | Equivalent to `g', but use an uppercase `E' in exponent form.
 *        a   | Convert floating point argument as [-]0xh.hhhhp[+-]dd,
 *            | which is consisted from optional sign, "0x", fraction part
 *            | as hexadecimal, "p", and exponential part as decimal.
 *        A   | Equivalent to `a', but use uppercase `X' and `P'.
 *
 *      Field |  Other Format
 *      ------+--------------------------------------------------------------
 *        c   | Argument is the numeric code for a single character or
 *            | a single character string itself.
 *        p   | The valuing of argument.inspect.
 *        s   | Argument is a string to be substituted.  If the format
 *            | sequence contains a precision, at most that many characters
 *            | will be copied.
 *        %   | A percent sign itself will be displayed.  No argument taken.
 *
 *  The flags modifies the behavior of the formats.
 *  The flag characters are:
 *
 *    Flag     | Applies to    | Meaning
 *    ---------+---------------+-----------------------------------------
 *    space    | bBdiouxX      | Leave a space at the start of
 *             | aAeEfgG       | non-negative numbers.
 *             | (numeric fmt) | For `o', `x', `X', `b' and `B', use
 *             |               | a minus sign with absolute value for
 *             |               | negative values.
 *    ---------+---------------+-----------------------------------------
 *    (digit)$ | all           | Specifies the absolute argument number
 *             |               | for this field.  Absolute and relative
 *             |               | argument numbers cannot be mixed in a
 *             |               | sprintf string.
 *    ---------+---------------+-----------------------------------------
 *     #       | bBoxX         | Use an alternative format.
 *             | aAeEfgG       | For the conversions `o', increase the precision
 *             |               | until the first digit will be `0' if
 *             |               | it is not formatted as complements.
 *             |               | For the conversions `x', `X', `b' and `B'
 *             |               | on non-zero, prefix the result with ``0x'',
 *             |               | ``0X'', ``0b'' and ``0B'', respectively.
 *             |               | For `a', `A', `e', `E', `f', `g', and 'G',
 *             |               | force a decimal point to be added,
 *             |               | even if no digits follow.
 *             |               | For `g' and 'G', do not remove trailing zeros.
 *    ---------+---------------+-----------------------------------------
 *    +        | bBdiouxX      | Add a leading plus sign to non-negative
 *             | aAeEfgG       | numbers.
 *             | (numeric fmt) | For `o', `x', `X', `b' and `B', use
 *             |               | a minus sign with absolute value for
 *             |               | negative values.
 *    ---------+---------------+-----------------------------------------
 *    -        | all           | Left-justify the result of this conversion.
 *    ---------+---------------+-----------------------------------------
 *    0 (zero) | bBdiouxX      | Pad with zeros, not spaces.
 *             | aAeEfgG       | For `o', `x', `X', `b' and `B', radix-1
 *             | (numeric fmt) | is used for negative numbers formatted as
 *             |               | complements.
 *    ---------+---------------+-----------------------------------------
 *    *        | all           | Use the next argument as the field width.
 *             |               | If negative, left-justify the result. If the
 *             |               | asterisk is followed by a number and a dollar
 *             |               | sign, use the indicated argument as the width.
 *
 *  Examples of flags:
 *
 *   # `+' and space flag specifies the sign of non-negative numbers.
 *   sprintf("%d", 123)  #=> "123"
 *   sprintf("%+d", 123) #=> "+123"
 *   sprintf("% d", 123) #=> " 123"
 *
 *   # `#' flag for `o' increases number of digits to show `0'.
 *   # `+' and space flag changes format of negative numbers.
 *   sprintf("%o", 123)   #=> "173"
 *   sprintf("%#o", 123)  #=> "0173"
 *   sprintf("%+o", -123) #=> "-173"
 *   sprintf("%o", -123)  #=> "..7605"
 *   sprintf("%#o", -123) #=> "..7605"
 *
 *   # `#' flag for `x' add a prefix `0x' for non-zero numbers.
 *   # `+' and space flag disables complements for negative numbers.
 *   sprintf("%x", 123)   #=> "7b"
 *   sprintf("%#x", 123)  #=> "0x7b"
 *   sprintf("%+x", -123) #=> "-7b"
 *   sprintf("%x", -123)  #=> "..f85"
 *   sprintf("%#x", -123) #=> "0x..f85"
 *   sprintf("%#x", 0)    #=> "0"
 *
 *   # `#' for `X' uses the prefix `0X'.
 *   sprintf("%X", 123)  #=> "7B"
 *   sprintf("%#X", 123) #=> "0X7B"
 *
 *   # `#' flag for `b' add a prefix `0b' for non-zero numbers.
 *   # `+' and space flag disables complements for negative numbers.
 *   sprintf("%b", 123)   #=> "1111011"
 *   sprintf("%#b", 123)  #=> "0b1111011"
 *   sprintf("%+b", -123) #=> "-1111011"
 *   sprintf("%b", -123)  #=> "..10000101"
 *   sprintf("%#b", -123) #=> "0b..10000101"
 *   sprintf("%#b", 0)    #=> "0"
 *
 *   # `#' for `B' uses the prefix `0B'.
 *   sprintf("%B", 123)  #=> "1111011"
 *   sprintf("%#B", 123) #=> "0B1111011"
 *
 *   # `#' for `e' forces to show the decimal point.
 *   sprintf("%.0e", 1)  #=> "1e+00"
 *   sprintf("%#.0e", 1) #=> "1.e+00"
 *
 *   # `#' for `f' forces to show the decimal point.
 *   sprintf("%.0f", 1234)  #=> "1234"
 *   sprintf("%#.0f", 1234) #=> "1234."
 *
 *   # `#' for `g' forces to show the decimal point.
 *   # It also disables stripping lowest zeros.
 *   sprintf("%g", 123.4)   #=> "123.4"
 *   sprintf("%#g", 123.4)  #=> "123.400"
 *   sprintf("%g", 123456)  #=> "123456"
 *   sprintf("%#g", 123456) #=> "123456."
 *
 *  The field width is an optional integer, followed optionally by a
 *  period and a precision.  The width specifies the minimum number of
 *  characters that will be written to the result for this field.
 *
 *  Examples of width:
 *
 *   # padding is done by spaces,       width=20
 *   # 0 or radix-1.             <------------------>
 *   sprintf("%20d", 123)   #=> "                 123"
 *   sprintf("%+20d", 123)  #=> "                +123"
 *   sprintf("%020d", 123)  #=> "00000000000000000123"
 *   sprintf("%+020d", 123) #=> "+0000000000000000123"
 *   sprintf("% 020d", 123) #=> " 0000000000000000123"
 *   sprintf("%-20d", 123)  #=> "123                 "
 *   sprintf("%-+20d", 123) #=> "+123                "
 *   sprintf("%- 20d", 123) #=> " 123                "
 *   sprintf("%020x", -123) #=> "..ffffffffffffffff85"
 *
 *  For
 *  numeric fields, the precision controls the number of decimal places
 *  displayed.  For string fields, the precision determines the maximum
 *  number of characters to be copied from the string.  (Thus, the format
 *  sequence <code>%10.10s</code> will always contribute exactly ten
 *  characters to the result.)
 *
 *  Examples of precisions:
 *
 *   # precision for `d', 'o', 'x' and 'b' is
 *   # minimum number of digits               <------>
 *   sprintf("%20.8d", 123)  #=> "            00000123"
 *   sprintf("%20.8o", 123)  #=> "            00000173"
 *   sprintf("%20.8x", 123)  #=> "            0000007b"
 *   sprintf("%20.8b", 123)  #=> "            01111011"
 *   sprintf("%20.8d", -123) #=> "           -00000123"
 *   sprintf("%20.8o", -123) #=> "            ..777605"
 *   sprintf("%20.8x", -123) #=> "            ..ffff85"
 *   sprintf("%20.8b", -11)  #=> "            ..110101"
 *
 *   # "0x" and "0b" for `#x' and `#b' is not counted for
 *   # precision but "0" for `#o' is counted.  <------>
 *   sprintf("%#20.8d", 123)  #=> "            00000123"
 *   sprintf("%#20.8o", 123)  #=> "            00000173"
 *   sprintf("%#20.8x", 123)  #=> "          0x0000007b"
 *   sprintf("%#20.8b", 123)  #=> "          0b01111011"
 *   sprintf("%#20.8d", -123) #=> "           -00000123"
 *   sprintf("%#20.8o", -123) #=> "            ..777605"
 *   sprintf("%#20.8x", -123) #=> "          0x..ffff85"
 *   sprintf("%#20.8b", -11)  #=> "          0b..110101"
 *
 *   # precision for `e' is number of
 *   # digits after the decimal point           <------>
 *   sprintf("%20.8e", 1234.56789) #=> "      1.23456789e+03"
 *
 *   # precision for `f' is number of
 *   # digits after the decimal point               <------>
 *   sprintf("%20.8f", 1234.56789) #=> "       1234.56789000"
 *
 *   # precision for `g' is number of
 *   # significant digits                          <------->
 *   sprintf("%20.8g", 1234.56789) #=> "           1234.5679"
 *
 *   #                                         <------->
 *   sprintf("%20.8g", 123456789)  #=> "       1.2345679e+08"
 *
 *   # precision for `s' is
 *   # maximum number of characters                    <------>
 *   sprintf("%20.8s", "string test") #=> "            string t"
 *
 *  Examples:
 *
 *     sprintf("%d %04x", 123, 123)               #=> "123 007b"
 *     sprintf("%08b '%4s'", 123, 123)            #=> "01111011 ' 123'"
 *     sprintf("%1$*2$s %2$d %1$s", "hello", 8)   #=> "   hello 8 hello"
 *     sprintf("%1$*2$s %2$d", "hello", -8)       #=> "hello    -8"
 *     sprintf("%+g:% g:%-g", 1.23, 1.23, 1.23)   #=> "+1.23: 1.23:1.23"
 *     sprintf("%u", -123)                        #=> "-123"
 *
 *  For more complex formatting, Ruby supports a reference by name.
 *  %<name>s style uses format style, but %{name} style doesn't.
 *
 *  Exapmles:
 *    sprintf("%<foo>d : %<bar>f", { :foo => 1, :bar => 2 })
 *      #=> 1 : 2.000000
 *    sprintf("%{foo}f", { :foo => 1 })
 *      # => "1f"
 */

VALUE
rb_f_sprintf(int argc, const VALUE *argv)
{
    return rb_str_format(argc - 1, argv + 1, GETNTHARG(0));
}

VALUE
rb_str_format(int argc, const VALUE *argv, VALUE fmt)
{
    rb_encoding *enc;
    const char *p, *end;
    char *buf;
    long blen, bsiz;
    VALUE result;

    long scanned = 0;
    int coderange = ENC_CODERANGE_7BIT;
    int width, prec, flags = FNONE;
    int nextarg = 1;
    int posarg = 0;
    int tainted = 0;
    VALUE nextvalue;
    VALUE tmp;
    VALUE str;
    volatile VALUE hash = Qundef;

#define CHECK_FOR_WIDTH(f)				 \
    if ((f) & FWIDTH) {					 \
	rb_raise(rb_eArgError, "width given twice");	 \
    }							 \
    if ((f) & FPREC0) {					 \
	rb_raise(rb_eArgError, "width after precision"); \
    }
#define CHECK_FOR_FLAGS(f)				 \
    if ((f) & FWIDTH) {					 \
	rb_raise(rb_eArgError, "flag after width");	 \
    }							 \
    if ((f) & FPREC0) {					 \
	rb_raise(rb_eArgError, "flag after precision"); \
    }

    ++argc;
    --argv;
    if (OBJ_TAINTED(fmt)) tainted = 1;
    StringValue(fmt);
    enc = rb_enc_get(fmt);
    fmt = rb_str_new4(fmt);
    p = RSTRING_PTR(fmt);
    end = p + RSTRING_LEN(fmt);
    blen = 0;
    bsiz = 120;
    result = rb_str_buf_new(bsiz);
    rb_enc_copy(result, fmt);
    buf = RSTRING_PTR(result);
    memset(buf, 0, bsiz);
    ENC_CODERANGE_SET(result, coderange);

    for (; p < end; p++) {
	const char *t;
	int n;
	ID id = 0;

	for (t = p; t < end && *t != '%'; t++) ;
	PUSH(p, t - p);
	if (coderange != ENC_CODERANGE_BROKEN && scanned < blen) {
	    scanned += rb_str_coderange_scan_restartable(buf+scanned, buf+blen, enc, &coderange);
	    ENC_CODERANGE_SET(result, coderange);
	}
	if (t >= end) {
	    /* end of fmt string */
	    goto sprint_exit;
	}
	p = t + 1;		/* skip `%' */

	width = prec = -1;
	nextvalue = Qundef;
      retry:
	switch (*p) {
	  default:
	    if (rb_enc_isprint(*p, enc))
		rb_raise(rb_eArgError, "malformed format string - %%%c", *p);
	    else
		rb_raise(rb_eArgError, "malformed format string");
	    break;

	  case ' ':
	    CHECK_FOR_FLAGS(flags);
	    flags |= FSPACE;
	    p++;
	    goto retry;

	  case '#':
	    CHECK_FOR_FLAGS(flags);
	    flags |= FSHARP;
	    p++;
	    goto retry;

	  case '+':
	    CHECK_FOR_FLAGS(flags);
	    flags |= FPLUS;
	    p++;
	    goto retry;

	  case '-':
	    CHECK_FOR_FLAGS(flags);
	    flags |= FMINUS;
	    p++;
	    goto retry;

	  case '0':
	    CHECK_FOR_FLAGS(flags);
	    flags |= FZERO;
	    p++;
	    goto retry;

	  case '1': case '2': case '3': case '4':
	  case '5': case '6': case '7': case '8': case '9':
	    n = 0;
	    GETNUM(n, width);
	    if (*p == '$') {
		if (nextvalue != Qundef) {
		    rb_raise(rb_eArgError, "value given twice - %d$", n);
		}
		nextvalue = GETPOSARG(n);
		p++;
		goto retry;
	    }
	    CHECK_FOR_WIDTH(flags);
	    width = n;
	    flags |= FWIDTH;
	    goto retry;

	  case '<':
	  case '{':
	    {
		const char *start = p;
		char term = (*p == '<') ? '>' : '}';

		for (; p < end && *p != term; ) {
		    p += rb_enc_mbclen(p, end, enc);
		}
		if (p >= end) {
		    rb_raise(rb_eArgError, "malformed name - unmatched parenthesis");
		}
		if (id) {
		    rb_raise(rb_eArgError, "name%.*s after <%s>",
			     (int)(p - start + 1), start, rb_id2name(id));
		}
		id = rb_intern3(start + 1, p - start - 1, enc);
		nextvalue = GETNAMEARG(ID2SYM(id), start, (int)(p - start + 1));
		if (nextvalue == Qundef) {
		    rb_raise(rb_eKeyError, "key%.*s not found", (int)(p - start + 1), start);
		}
		if (term == '}') goto format_s;
		p++;
		goto retry;
	    }

	  case '*':
	    CHECK_FOR_WIDTH(flags);
	    flags |= FWIDTH;
	    GETASTER(width);
	    if (width < 0) {
		flags |= FMINUS;
		width = -width;
	    }
	    p++;
	    goto retry;

	  case '.':
	    if (flags & FPREC0) {
		rb_raise(rb_eArgError, "precision given twice");
	    }
	    flags |= FPREC|FPREC0;

	    prec = 0;
	    p++;
	    if (*p == '*') {
		GETASTER(prec);
		if (prec < 0) {	/* ignore negative precision */
		    flags &= ~FPREC;
		}
		p++;
		goto retry;
	    }

	    GETNUM(prec, precision);
	    goto retry;

	  case '\n':
	  case '\0':
	    p--;
	  case '%':
	    if (flags != FNONE) {
		rb_raise(rb_eArgError, "invalid format character - %%");
	    }
	    PUSH("%", 1);
	    break;

	  case 'c':
	    {
		VALUE val = GETARG();
		VALUE tmp;
		unsigned int c;
		int n;

		tmp = rb_check_string_type(val);
		if (!NIL_P(tmp)) {
		    if (rb_enc_strlen(RSTRING_PTR(tmp),RSTRING_END(tmp),enc) != 1) {
			rb_raise(rb_eArgError, "%%c requires a character");
		    }
		    c = rb_enc_codepoint_len(RSTRING_PTR(tmp), RSTRING_END(tmp), &n, enc);
		}
		else {
		    c = NUM2INT(val);
		    n = rb_enc_codelen(c, enc);
		}
		if (n <= 0) {
		    rb_raise(rb_eArgError, "invalid character");
		}
		if (!(flags & FWIDTH)) {
		    CHECK(n);
		    rb_enc_mbcput(c, &buf[blen], enc);
		    blen += n;
		}
		else if ((flags & FMINUS)) {
		    CHECK(n);
		    rb_enc_mbcput(c, &buf[blen], enc);
		    blen += n;
		    FILL(' ', width-1);
		}
		else {
		    FILL(' ', width-1);
		    CHECK(n);
		    rb_enc_mbcput(c, &buf[blen], enc);
		    blen += n;
		}
	    }
	    break;

	  case 's':
	  case 'p':
	  format_s:
	    {
		VALUE arg = GETARG();
		long len, slen;

		if (*p == 'p') arg = rb_inspect(arg);
		str = rb_obj_as_string(arg);
		if (OBJ_TAINTED(str)) tainted = 1;
		len = RSTRING_LEN(str);
		rb_str_set_len(result, blen);
		if (coderange != ENC_CODERANGE_BROKEN && scanned < blen) {
		    int cr = coderange;
		    scanned += rb_str_coderange_scan_restartable(buf+scanned, buf+blen, enc, &cr);
		    ENC_CODERANGE_SET(result,
				      (cr == ENC_CODERANGE_UNKNOWN ?
				       ENC_CODERANGE_BROKEN : (coderange = cr)));
		}
		enc = rb_enc_check(result, str);
		if (flags&(FPREC|FWIDTH)) {
		    slen = rb_enc_strlen(RSTRING_PTR(str),RSTRING_END(str),enc);
		    if (slen < 0) {
			rb_raise(rb_eArgError, "invalid mbstring sequence");
		    }
		    if ((flags&FPREC) && (prec < slen)) {
			char *p = rb_enc_nth(RSTRING_PTR(str), RSTRING_END(str),
					     prec, enc);
			slen = prec;
			len = p - RSTRING_PTR(str);
		    }
		    /* need to adjust multi-byte string pos */
		    if ((flags&FWIDTH) && (width > slen)) {
			width -= (int)slen;
			if (!(flags&FMINUS)) {
			    CHECK(width);
			    while (width--) {
				buf[blen++] = ' ';
			    }
			}
			CHECK(len);
			memcpy(&buf[blen], RSTRING_PTR(str), len);
			blen += len;
			if (flags&FMINUS) {
			    CHECK(width);
			    while (width--) {
				buf[blen++] = ' ';
			    }
			}
			rb_enc_associate(result, enc);
			break;
		    }
		}
		PUSH(RSTRING_PTR(str), len);
		rb_enc_associate(result, enc);
	    }
	    break;

	  case 'd':
	  case 'i':
	  case 'o':
	  case 'x':
	  case 'X':
	  case 'b':
	  case 'B':
	  case 'u':
	    {
		volatile VALUE tmp1;
		volatile VALUE val = GETARG();
		char fbuf[32], nbuf[64], *s;
		const char *prefix = 0;
		int sign = 0, dots = 0;
		char sc = 0;
		long v = 0;
		int base, bignum = 0;
		int len;

		switch (*p) {
		  case 'd':
		  case 'i':
		  case 'u':
		    sign = 1; break;
		  case 'o':
		  case 'x':
		  case 'X':
		  case 'b':
		  case 'B':
		    if (flags&(FPLUS|FSPACE)) sign = 1;
		    break;
		}
		if (flags & FSHARP) {
		    switch (*p) {
		      case 'o':
			prefix = "0"; break;
		      case 'x':
			prefix = "0x"; break;
		      case 'X':
			prefix = "0X"; break;
		      case 'b':
			prefix = "0b"; break;
		      case 'B':
			prefix = "0B"; break;
		    }
		}

	      bin_retry:
		switch (TYPE(val)) {
		  case T_FLOAT:
		    if (FIXABLE(RFLOAT_VALUE(val))) {
			val = LONG2FIX((long)RFLOAT_VALUE(val));
			goto bin_retry;
		    }
		    val = rb_dbl2big(RFLOAT_VALUE(val));
		    if (FIXNUM_P(val)) goto bin_retry;
		    bignum = 1;
		    break;
		  case T_STRING:
		    val = rb_str_to_inum(val, 0, TRUE);
		    goto bin_retry;
		  case T_BIGNUM:
		    bignum = 1;
		    break;
		  case T_FIXNUM:
		    v = FIX2LONG(val);
		    break;
		  default:
		    val = rb_Integer(val);
		    goto bin_retry;
		}

		switch (*p) {
		  case 'o':
		    base = 8; break;
		  case 'x':
		  case 'X':
		    base = 16; break;
		  case 'b':
		  case 'B':
		    base = 2; break;
		  case 'u':
		  case 'd':
		  case 'i':
		  default:
		    base = 10; break;
		}

		if (!bignum) {
		    if (base == 2) {
			val = rb_int2big(v);
			goto bin_retry;
		    }
		    if (sign) {
			char c = *p;
			if (c == 'i') c = 'd'; /* %d and %i are identical */
			if (v < 0) {
			    v = -v;
			    sc = '-';
			    width--;
			}
			else if (flags & FPLUS) {
			    sc = '+';
			    width--;
			}
			else if (flags & FSPACE) {
			    sc = ' ';
			    width--;
			}
			snprintf(fbuf, sizeof(fbuf), "%%l%c", c);
			snprintf(nbuf, sizeof(nbuf), fbuf, v);
			s = nbuf;
		    }
		    else {
			s = nbuf;
			if (v < 0) {
			    dots = 1;
			}
			snprintf(fbuf, sizeof(fbuf), "%%l%c", *p == 'X' ? 'x' : *p);
			snprintf(++s, sizeof(nbuf) - 1, fbuf, v);
			if (v < 0) {
			    char d = 0;

			    s = remove_sign_bits(s, base);
			    switch (base) {
			      case 16:
				d = 'f'; break;
			      case 8:
				d = '7'; break;
			    }
			    if (d && *s != d) {
				*--s = d;
			    }
			}
		    }
		    len = (int)strlen(s);
		}
		else {
		    if (sign) {
			tmp = rb_big2str(val, base);
			s = RSTRING_PTR(tmp);
			if (s[0] == '-') {
			    s++;
			    sc = '-';
			    width--;
			}
			else if (flags & FPLUS) {
			    sc = '+';
			    width--;
			}
			else if (flags & FSPACE) {
			    sc = ' ';
			    width--;
			}
		    }
		    else {
			if (!RBIGNUM_SIGN(val)) {
			    val = rb_big_clone(val);
			    rb_big_2comp(val);
			}
			tmp1 = tmp = rb_big2str0(val, base, RBIGNUM_SIGN(val));
			s = RSTRING_PTR(tmp);
			if (*s == '-') {
			    dots = 1;
			    if (base == 10) {
				rb_warning("negative number for %%u specifier");
			    }
			    s = remove_sign_bits(++s, base);
			    switch (base) {
			      case 16:
				if (s[0] != 'f') *--s = 'f'; break;
			      case 8:
				if (s[0] != '7') *--s = '7'; break;
			      case 2:
				if (s[0] != '1') *--s = '1'; break;
			    }
			}
		    }
		    len = rb_long2int(RSTRING_END(tmp) - s);
		}

		if (dots) {
		    prec -= 2;
		    width -= 2;
		}

		if (*p == 'X') {
		    char *pp = s;
		    int c;
		    while ((c = (int)(unsigned char)*pp) != 0) {
			*pp = rb_enc_toupper(c, enc);
			pp++;
		    }
		}
		if (prefix && !prefix[1]) { /* octal */
		    if (dots) {
			prefix = 0;
		    }
		    else if (len == 1 && *s == '0') {
			len = 0;
			if (flags & FPREC) prec--;
		    }
		    else if ((flags & FPREC) && (prec > len)) {
			prefix = 0;
		    }
		}
		else if (len == 1 && *s == '0') {
		    prefix = 0;
		}
		if (prefix) {
		    width -= (int)strlen(prefix);
		}
		if ((flags & (FZERO|FMINUS|FPREC)) == FZERO) {
		    prec = width;
		    width = 0;
		}
		else {
		    if (prec < len) {
			if (!prefix && prec == 0 && len == 1 && *s == '0') len = 0;
			prec = len;
		    }
		    width -= prec;
		}
		if (!(flags&FMINUS)) {
		    CHECK(width);
		    while (width-- > 0) {
			buf[blen++] = ' ';
		    }
		}
		if (sc) PUSH(&sc, 1);
		if (prefix) {
		    int plen = (int)strlen(prefix);
		    PUSH(prefix, plen);
		}
		CHECK(prec - len);
		if (dots) PUSH("..", 2);
		if (!bignum && v < 0) {
		    char c = sign_bits(base, p);
		    while (len < prec--) {
			buf[blen++] = c;
		    }
		}
		else if ((flags & (FMINUS|FPREC)) != FMINUS) {
		    char c;

		    if (!sign && bignum && !RBIGNUM_SIGN(val))
			c = sign_bits(base, p);
		    else
			c = '0';
		    while (len < prec--) {
			buf[blen++] = c;
		    }
		}
		PUSH(s, len);
		CHECK(width);
		while (width-- > 0) {
		    buf[blen++] = ' ';
		}
	    }
	    break;

	  case 'f':
	  case 'g':
	  case 'G':
	  case 'e':
	  case 'E':
	  case 'a':
	  case 'A':
	    {
		VALUE val = GETARG();
		double fval;
		int i, need = 6;
		char fbuf[32];

		fval = RFLOAT_VALUE(rb_Float(val));
		if (isnan(fval) || isinf(fval)) {
		    const char *expr;

		    if (isnan(fval)) {
			expr = "NaN";
		    }
		    else {
			expr = "Inf";
		    }
		    need = (int)strlen(expr);
		    if ((!isnan(fval) && fval < 0.0) || (flags & FPLUS))
			need++;
		    if ((flags & FWIDTH) && need < width)
			need = width;

		    CHECK(need + 1);
		    snprintf(&buf[blen], need + 1, "%*s", need, "");
		    if (flags & FMINUS) {
			if (!isnan(fval) && fval < 0.0)
			    buf[blen++] = '-';
			else if (flags & FPLUS)
			    buf[blen++] = '+';
			else if (flags & FSPACE)
			    blen++;
			memcpy(&buf[blen], expr, strlen(expr));
		    }
		    else {
			if (!isnan(fval) && fval < 0.0)
			    buf[blen + need - strlen(expr) - 1] = '-';
			else if (flags & FPLUS)
			    buf[blen + need - strlen(expr) - 1] = '+';
			else if ((flags & FSPACE) && need > width)
			    blen++;
			memcpy(&buf[blen + need - strlen(expr)], expr,
			       strlen(expr));
		    }
		    blen += strlen(&buf[blen]);
		    break;
		}

		fmt_setup(fbuf, sizeof(fbuf), *p, flags, width, prec);
		need = 0;
		if (*p != 'e' && *p != 'E') {
		    i = INT_MIN;
		    frexp(fval, &i);
		    if (i > 0)
			need = BIT_DIGITS(i);
		}
		need += (flags&FPREC) ? prec : 6;
		if ((flags&FWIDTH) && need < width)
		    need = width;
		need += 20;

		CHECK(need);
		snprintf(&buf[blen], need, fbuf, fval);
		blen += strlen(&buf[blen]);
	    }
	    break;
	}
	flags = FNONE;
    }

  sprint_exit:
    /* XXX - We cannot validate the number of arguments if (digit)$ style used.
     */
    if (posarg >= 0 && nextarg < argc) {
	const char *mesg = "too many arguments for format string";
	if (RTEST(ruby_debug)) rb_raise(rb_eArgError, "%s", mesg);
	if (RTEST(ruby_verbose)) rb_warn("%s", mesg);
    }
    rb_str_resize(result, blen);

    if (tainted) OBJ_TAINT(result);
    return result;
}

static void
fmt_setup(char *buf, size_t size, int c, int flags, int width, int prec)
{
    char *end = buf + size;
    *buf++ = '%';
    if (flags & FSHARP) *buf++ = '#';
    if (flags & FPLUS)  *buf++ = '+';
    if (flags & FMINUS) *buf++ = '-';
    if (flags & FZERO)  *buf++ = '0';
    if (flags & FSPACE) *buf++ = ' ';

    if (flags & FWIDTH) {
	snprintf(buf, end - buf, "%d", width);
	buf += strlen(buf);
    }

    if (flags & FPREC) {
	snprintf(buf, end - buf, ".%d", prec);
	buf += strlen(buf);
    }

    *buf++ = c;
    *buf = '\0';
}

#undef FILE
#define FILE rb_printf_buffer
#define __sbuf rb_printf_sbuf
#define __sFILE rb_printf_sfile
#undef feof
#undef ferror
#undef clearerr
#undef fileno
#if SIZEOF_LONG < SIZEOF_VOIDP
# if  SIZEOF_LONG_LONG == SIZEOF_VOIDP
#  define _HAVE_SANE_QUAD_
#  define _HAVE_LLP64_
#  define quad_t LONG_LONG
#  define u_quad_t unsigned LONG_LONG
# endif
#elif SIZEOF_LONG != SIZEOF_LONG_LONG && SIZEOF_LONG_LONG == 8
# define _HAVE_SANE_QUAD_
# define quad_t LONG_LONG
# define u_quad_t unsigned LONG_LONG
#endif
#define FLOATING_POINT 1
#define BSD__dtoa ruby_dtoa
#define BSD__hdtoa ruby_hdtoa
#include "vsnprintf.c"

static int
ruby__sfvwrite(register rb_printf_buffer *fp, register struct __suio *uio)
{
    struct __siov *iov;
    VALUE result = (VALUE)fp->_bf._base;
    char *buf = (char*)fp->_p;
    size_t len, n;
    size_t blen = buf - RSTRING_PTR(result), bsiz = fp->_w;

    if (RBASIC(result)->klass) {
	rb_raise(rb_eRuntimeError, "rb_vsprintf reentered");
    }
    if ((len = uio->uio_resid) == 0)
	return 0;
    CHECK(len);
    buf += blen;
    fp->_w = bsiz;
    for (iov = uio->uio_iov; len > 0; ++iov) {
	MEMCPY(buf, iov->iov_base, char, n = iov->iov_len);
	buf += n;
	len -= n;
    }
    fp->_p = (unsigned char *)buf;
    return 0;
}

VALUE
rb_enc_vsprintf(rb_encoding *enc, const char *fmt, va_list ap)
{
    rb_printf_buffer f;
    VALUE result;

    f._flags = __SWR | __SSTR;
    f._bf._size = 0;
    f._w = 120;
    result = rb_str_buf_new(f._w);
    if (enc) rb_enc_associate(result, enc);
    f._bf._base = (unsigned char *)result;
    f._p = (unsigned char *)RSTRING_PTR(result);
    RBASIC(result)->klass = 0;
    f.vwrite = ruby__sfvwrite;
    BSD_vfprintf(&f, fmt, ap);
    RBASIC(result)->klass = rb_cString;
    rb_str_resize(result, (char *)f._p - RSTRING_PTR(result));

    return result;
}

VALUE
rb_enc_sprintf(rb_encoding *enc, const char *format, ...)
{
    VALUE result;
    va_list ap;

    va_start(ap, format);
    result = rb_enc_vsprintf(enc, format, ap);
    va_end(ap);

    return result;
}

VALUE
rb_vsprintf(const char *fmt, va_list ap)
{
    return rb_enc_vsprintf(NULL, fmt, ap);
}

VALUE
rb_sprintf(const char *format, ...)
{
    VALUE result;
    va_list ap;

    va_start(ap, format);
    result = rb_vsprintf(format, ap);
    va_end(ap);

    return result;
}

VALUE
rb_str_vcatf(VALUE str, const char *fmt, va_list ap)
{
    rb_printf_buffer f;
    VALUE klass;

    StringValue(str);
    rb_str_modify(str);
    f._flags = __SWR | __SSTR;
    f._bf._size = 0;
    f._w = rb_str_capacity(str);
    f._bf._base = (unsigned char *)str;
    f._p = (unsigned char *)RSTRING_END(str);
    klass = RBASIC(str)->klass;
    RBASIC(str)->klass = 0;
    f.vwrite = ruby__sfvwrite;
    BSD_vfprintf(&f, fmt, ap);
    RBASIC(str)->klass = klass;
    rb_str_resize(str, (char *)f._p - RSTRING_PTR(str));

    return str;
}

VALUE
rb_str_catf(VALUE str, const char *format, ...)
{
    va_list ap;

    va_start(ap, format);
    str = rb_str_vcatf(str, format, ap);
    va_end(ap);

    return str;
}