stdio-common/vfprintf.c

   1 /* Copyright (C) 1991, 92, 93, 94, 95, 96 Free Software Foundation, Inc.
   2 This file is part of the GNU C Library.
   3
   4 The GNU C Library is free software; you can redistribute it and/or
   5 modify it under the terms of the GNU Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 License, or (at your option) any later version.
   8
   9 The GNU C Library is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #include <ctype.h>
  20 #include <errno.h>
  21 #include <float.h>
  22 #include <limits.h>
  23 #include <math.h>
  24 #include <printf.h>
  25 #include <stdarg.h>
  26 #include <stdlib.h>
  27 #include <string.h>
  28 #include <printf.h>
  29 #include <stddef.h>
  30 #include "_itoa.h"
  31 #include "../locale/localeinfo.h"
  32
  33 /* Include the shared code for parsing the format string.  */
  34 #include "printf-parse.h"
  35
  36
  37 /* This function from the GNU C library is also used in libio.
  38    To compile for use in libio, compile with -DUSE_IN_LIBIO.  */
  39
  40 #ifdef USE_IN_LIBIO
  41 /* This code is for use in libio.  */
  42 #include <libioP.h>
  43 #define PUT(f, s, n)    _IO_sputn (f, s, n)
  44 #define PAD(padchar)                                                          \
  45   if (specs[cnt].info.width > 0)                                              \
  46     done += _IO_padn (s, padchar, specs[cnt].info.width)
  47 #define PUTC(c, f)      _IO_putc (c, f)
  48 #define vfprintf        _IO_vfprintf
  49 #define size_t          _IO_size_t
  50 #define FILE            _IO_FILE
  51 #define va_list         _IO_va_list
  52 #undef  BUFSIZ
  53 #define BUFSIZ          _IO_BUFSIZ
  54 #define ARGCHECK(s, format)                                                   \
  55   do                                                                          \
  56     {                                                                         \
  57       /* Check file argument for consistence.  */                             \
  58       CHECK_FILE (s, -1);                                                     \
  59       if (s->_flags & _IO_NO_WRITES || format == NULL)                        \
  60         {                                                                     \
  61           MAYBE_SET_EINVAL;                                                   \
  62           return -1;                                                          \
  63         }                                                                     \
  64     } while (0)
  65 #define UNBUFFERED_P(s) ((s)->_IO_file_flags & _IO_UNBUFFERED)
  66 #else /* ! USE_IN_LIBIO */
  67 /* This code is for use in the GNU C library.  */
  68 #include <stdio.h>
  69 #define PUTC(c, f)      putc (c, f)
  70 #define PUT(f, s, n)    fwrite (s, 1, n, f)
  71 ssize_t __printf_pad __P ((FILE *, char pad, size_t n));
  72 #define PAD(padchar)                                                          \
  73   if (specs[cnt].info.width > 0)                                              \
  74     { if (__printf_pad (s, padchar, specs[cnt].info.width) == -1)             \
  75         return -1; else done += specs[cnt].info.width; }
  76 #define ARGCHECK(s, format) \
  77   do                                                                          \
  78     {                                                                         \
  79       /* Check file argument for consistence.  */                             \
  80       if (!__validfp(s) || !s->__mode.__write || format == NULL)              \
  81         {                                                                     \
  82           errno = EINVAL;                                                     \
  83           return -1;                                                          \
  84         }                                                                     \
  85       if (!s->__seen)                                                         \
  86         {                                                                     \
  87           if (__flshfp (s, EOF) == EOF)                                       \
  88             return -1;                                                        \
  89         }                                                                     \
  90     } while (0)
  91 #define UNBUFFERED_P(s) ((s)->__buffer == NULL)
  92 #endif /* USE_IN_LIBIO */
  93
  94
  95 #define outchar(x)                                                            \
  96   do                                                                          \
  97     {                                                                         \
  98       register const int outc = (x);                                          \
  99       if (PUTC (outc, s) == EOF)                                              \
 100         return -1;                                                            \
 101       else                                                                    \
 102         ++done;                                                               \
 103     } while (0)
 104
 105 #define outstring(string, len)                                                \
 106   do                                                                          \
 107     {                                                                         \
 108       if (len > 20)                                                           \
 109         {                                                                     \
 110           if (PUT (s, string, len) != len)                                    \
 111             return -1;                                                        \
 112           done += len;                                                        \
 113         }                                                                     \
 114       else                                                                    \
 115         {                                                                     \
 116           register const char *cp = string;                                   \
 117           register int l = len;                                               \
 118           while (l-- > 0)                                                     \
 119             outchar (*cp++);                                                  \
 120         }                                                                     \
 121     } while (0)
 122
 123 /* Helper function to provide temporary buffering for unbuffered streams.  */
 124 static int buffered_vfprintf __P ((FILE *stream, const char *fmt, va_list));
 125
 126 static printf_function printf_unknown;
 127
 128 extern printf_function **__printf_function_table;
 129
 130 static char *group_number __P ((char *, char *, const char *, wchar_t));
 131
 132
 133 int
 134 vfprintf (s, format, ap)
 135     register FILE *s;
 136     const char *format;
 137     va_list ap;
 138 {
 139   /* The character used as thousands separator.  */
 140   wchar_t thousands_sep;
 141
 142   /* The string describing the size of groups of digits.  */
 143   const char *grouping;
 144
 145   /* Array with information about the needed arguments.  This has to be
 146      dynamically extendable.  */
 147   size_t nspecs;
 148   size_t nspecs_max;
 149   struct printf_spec *specs;
 150
 151   /* The number of arguments the format string requests.  This will
 152      determine the size of the array needed to store the argument
 153      attributes.  */
 154   size_t nargs;
 155   int *args_type;
 156   union printf_arg *args_value;
 157
 158   /* Positional parameters refer to arguments directly.  This could also
 159      determine the maximum number of arguments.  Track the maximum number.  */
 160   size_t max_ref_arg;
 161
 162   /* End of leading constant string.  */
 163   const char *lead_str_end;
 164
 165   /* Number of characters written.  */
 166   register size_t done = 0;
 167
 168   /* Running pointer through format string.  */
 169   const char *f;
 170
 171   /* Just a counter.  */
 172   int cnt;
 173
 174   ARGCHECK (s, format);
 175
 176   if (UNBUFFERED_P (s))
 177     /* Use a helper function which will allocate a local temporary buffer
 178        for the stream and then call us again.  */
 179     return buffered_vfprintf (s, format, ap);
 180
 181   /* Reset multibyte characters to their initial state.  */
 182   (void) mblen ((char *) NULL, 0);
 183
 184   /* Figure out the thousands separator character.  */
 185   if (mbtowc (&thousands_sep, _NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP),
 186               strlen (_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP))) <= 0)
 187     thousands_sep = (wchar_t) *_NL_CURRENT (LC_NUMERIC, THOUSANDS_SEP);
 188   grouping = _NL_CURRENT (LC_NUMERIC, GROUPING);
 189   if (*grouping == '\0' || *grouping == CHAR_MAX || thousands_sep == L'\0')
 190     grouping = NULL;
 191
 192   nspecs_max = 32;              /* A more or less arbitrary start value.  */
 193   specs = alloca (nspecs_max * sizeof (struct printf_spec));
 194   nspecs = 0;
 195   nargs = 0;
 196   max_ref_arg = 0;
 197
 198   /* Find the first format specifier.  */
 199   lead_str_end = find_spec (format);
 200
 201   for (f = lead_str_end; *f != '\0'; f = specs[nspecs++].next_fmt)
 202     {
 203       if (nspecs >= nspecs_max)
 204         {
 205           /* Extend the array of format specifiers.  */
 206           struct printf_spec *old = specs;
 207
 208           nspecs_max *= 2;
 209           specs = alloca (nspecs_max * sizeof (struct printf_spec));
 210           if (specs == &old[nspecs])
 211             /* Stack grows up, OLD was the last thing allocated; extend it.  */
 212             nspecs_max += nspecs_max / 2;
 213           else
 214             {
 215               /* Copy the old array's elements to the new space.  */
 216               memcpy (specs, old, nspecs * sizeof (struct printf_spec));
 217               if (old == &specs[nspecs])
 218                 /* Stack grows down, OLD was just below the new SPECS.
 219                    We can use that space when the new space runs out.  */
 220                 nspecs_max += nspecs_max / 2;
 221             }
 222         }
 223
 224       /* Parse the format specifier.  */
 225       nargs += parse_one_spec (f, nargs, &specs[nspecs], &max_ref_arg);
 226     }
 227
 228   /* Determine the number of arguments the format string consumes.  */
 229   nargs = MAX (nargs, max_ref_arg);
 230
 231   /* Allocate memory for the argument descriptions.  */
 232   args_type = alloca (nargs * sizeof (int));
 233   memset (args_type, 0, nargs * sizeof (int));
 234   args_value = alloca (nargs * sizeof (union printf_arg));
 235
 236   /* XXX Could do sanity check here: If any element in ARGS_TYPE is
 237      still zero after this loop, format is invalid.  For now we simply
 238      use 0 as the value.  */
 239
 240   /* Fill in the types of all the arguments.  */
 241   for (cnt = 0; cnt < nspecs; ++cnt)
 242     {
 243       /* If the width is determined by an argument this is an int.  */
 244       if (specs[cnt].width_arg != -1)
 245         args_type[specs[cnt].width_arg] = PA_INT;
 246
 247       /* If the precision is determined by an argument this is an int.  */
 248       if (specs[cnt].prec_arg != -1)
 249         args_type[specs[cnt].prec_arg] = PA_INT;
 250
 251       switch (specs[cnt].ndata_args)
 252         {
 253         case 0:                 /* No arguments.  */
 254           break;
 255         case 1:                 /* One argument; we already have the type.  */
 256           args_type[specs[cnt].data_arg] = specs[cnt].data_arg_type;
 257           break;
 258         default:
 259           /* We have more than one argument for this format spec.  We must
 260              call the arginfo function again to determine all the types.  */
 261           (void) (*__printf_arginfo_table[specs[cnt].info.spec])
 262             (&specs[cnt].info,
 263              specs[cnt].ndata_args, &args_type[specs[cnt].data_arg]);
 264           break;
 265         }
 266     }
 267
 268   /* Now we know all the types and the order.  Fill in the argument values.  */
 269   for (cnt = 0; cnt < nargs; ++cnt)
 270     switch (args_type[cnt])
 271       {
 272 #define T(tag, mem, type)                                                     \
 273       case tag:                                                               \
 274         args_value[cnt].mem = va_arg (ap, type);                              \
 275         break
 276
 277         T (PA_CHAR, pa_char, int); /* Promoted.  */
 278         T (PA_INT|PA_FLAG_SHORT, pa_short_int, int); /* Promoted.  */
 279         T (PA_INT, pa_int, int);
 280         T (PA_INT|PA_FLAG_LONG, pa_long_int, long int);
 281         T (PA_INT|PA_FLAG_LONG_LONG, pa_long_long_int, long long int);
 282         T (PA_FLOAT, pa_float, double); /* Promoted.  */
 283         T (PA_DOUBLE, pa_double, double);
 284         T (PA_DOUBLE|PA_FLAG_LONG_DOUBLE, pa_long_double, long double);
 285         T (PA_STRING, pa_string, const char *);
 286         T (PA_POINTER, pa_pointer, void *);
 287 #undef T
 288       default:
 289         if ((args_type[cnt] & PA_FLAG_PTR) != 0)
 290           args_value[cnt].pa_pointer = va_arg (ap, void *);
 291         else
 292           args_value[cnt].pa_long_double = 0.0;
 293         break;
 294       }
 295
 296   /* Write the literal text before the first format.  */
 297   outstring (format, lead_str_end - format);
 298
 299   /* Now walk through all format specifiers and process them.  */
 300   for (cnt = 0; cnt < nspecs; ++cnt)
 301     {
 302       printf_function *function; /* Auxiliary function to do output.  */
 303       int is_neg;               /* Decimal integer is negative.  */
 304       int base;                 /* Base of a number to be written.  */
 305       unsigned long long int num; /* Integral number to be written.  */
 306       const char *str;          /* String to be written.  */
 307       char errorbuf[1024];      /* Buffer sometimes used by %m.  */
 308
 309       if (specs[cnt].width_arg != -1)
 310         {
 311           /* Extract the field width from an argument.  */
 312           specs[cnt].info.width = args_value[specs[cnt].width_arg].pa_int;
 313
 314           if (specs[cnt].info.width < 0)
 315             /* If the width value is negative left justification is selected
 316                and the value is taken as being positive.  */
 317             {
 318               specs[cnt].info.width = -specs[cnt].info.width;
 319               specs[cnt].info.left = 1;
 320             }
 321         }
 322
 323       if (specs[cnt].prec_arg != -1)
 324         {
 325           /* Extract the precision from an argument.  */
 326           specs[cnt].info.prec = args_value[specs[cnt].prec_arg].pa_int;
 327
 328           if (specs[cnt].info.prec < 0)
 329             /* If the precision is negative the precision is omitted.  */
 330             specs[cnt].info.prec = -1;
 331         }
 332
 333       /* Check for a user-defined handler for this spec.  */
 334       function = (__printf_function_table == NULL ? NULL :
 335                   __printf_function_table[specs[cnt].info.spec]);
 336
 337       if (function != NULL)
 338       use_function:             /* Built-in formats with helpers use this.  */
 339         {
 340           int function_done;
 341           unsigned int i;
 342           const void *ptr[specs[cnt].ndata_args];
 343
 344           /* Fill in an array of pointers to the argument values.  */
 345           for (i = 0; i < specs[cnt].ndata_args; ++i)
 346             ptr[i] = &args_value[specs[cnt].data_arg + i];
 347
 348           /* Call the function.  */
 349           function_done = (*function) (s, &specs[cnt].info, ptr);
 350
 351           /* If an error occured don't do any further work.  */
 352           if (function_done < 0)
 353             return -1;
 354
 355           done += function_done;
 356         }
 357       else
 358         switch (specs[cnt].info.spec)
 359           {
 360           case '%':
 361             /* Write a literal "%".  */
 362             outchar ('%');
 363             break;
 364           case 'i':
 365           case 'd':
 366             {
 367               long long int signed_num;
 368
 369               /* Decimal integer.  */
 370               base = 10;
 371               if (specs[cnt].info.is_longlong)
 372                 signed_num = args_value[specs[cnt].data_arg].pa_long_long_int;
 373               else if (specs[cnt].info.is_long)
 374                 signed_num = args_value[specs[cnt].data_arg].pa_long_int;
 375               else if (!specs[cnt].info.is_short)
 376                 signed_num = args_value[specs[cnt].data_arg].pa_int;
 377               else
 378                 signed_num = args_value[specs[cnt].data_arg].pa_short_int;
 379
 380               is_neg = signed_num < 0;
 381               num = is_neg ? (- signed_num) : signed_num;
 382               goto number;
 383             }
 384
 385           case 'u':
 386             /* Decimal unsigned integer.  */
 387             base = 10;
 388             goto unsigned_number;
 389
 390           case 'o':
 391             /* Octal unsigned integer.  */
 392             base = 8;
 393             goto unsigned_number;
 394
 395           case 'X':
 396             /* Hexadecimal unsigned integer.  */
 397           case 'x':
 398             /* Hex with lower-case digits.  */
 399             base = 16;
 400
 401           unsigned_number:
 402             /* Unsigned number of base BASE.  */
 403
 404             if (specs[cnt].info.is_longlong)
 405               num = args_value[specs[cnt].data_arg].pa_u_long_long_int;
 406             else if (specs[cnt].info.is_long)
 407               num = args_value[specs[cnt].data_arg].pa_u_long_int;
 408             else if (!specs[cnt].info.is_short)
 409               num = args_value[specs[cnt].data_arg].pa_u_int;
 410             else
 411               num = args_value[specs[cnt].data_arg].pa_u_short_int;
 412
 413             /* ANSI only specifies the `+' and
 414                ` ' flags for signed conversions.  */
 415             is_neg = 0;
 416             specs[cnt].info.showsign = 0;
 417             specs[cnt].info.space = 0;
 418
 419           number:
 420             /* Number of base BASE.  */
 421             {
 422               char work[BUFSIZ];
 423               char *const workend = &work[sizeof(work) - 1];
 424               register char *w;
 425
 426               if (specs[cnt].info.prec == -1)
 427                   /* Supply a default precision if none was given.  */
 428                   specs[cnt].info.prec = 1;
 429               else
 430                 /* We have to take care for the '0' flag.  If a
 431                    precision is given it must be ignored.  */
 432                 specs[cnt].info.pad = ' ';
 433
 434               /* If the precision is 0 and the number is 0 nothing has
 435                  to be written for the number.  */
 436               if (specs[cnt].info.prec == 0 && num == 0)
 437                 w = workend;
 438               else
 439                 {
 440                   /* Put the number in WORK.  */
 441                   w = _itoa (num, workend + 1, base,
 442                              specs[cnt].info.spec == 'X');
 443                   w -= 1;
 444                   if (specs[cnt].info.group && grouping)
 445                     w = group_number (w, workend, grouping, thousands_sep);
 446                 }
 447               specs[cnt].info.width -= workend - w;
 448               specs[cnt].info.prec -= workend - w;
 449
 450               if (num != 0 && specs[cnt].info.alt && base == 8
 451                   && specs[cnt].info.prec <= 0)
 452                 {
 453                   /* Add octal marker.  */
 454                   *w-- = '0';
 455                   --specs[cnt].info.width;
 456                 }
 457
 458               if (specs[cnt].info.prec > 0)
 459                 {
 460                   /* Add zeros to the precision.  */
 461                   specs[cnt].info.width -= specs[cnt].info.prec;
 462                   while (specs[cnt].info.prec-- > 0)
 463                     *w-- = '0';
 464                 }
 465
 466               if (num != 0 && specs[cnt].info.alt && base == 16)
 467                 /* Account for 0X hex marker.  */
 468                 specs[cnt].info.width -= 2;
 469
 470               if (is_neg || specs[cnt].info.showsign || specs[cnt].info.space)
 471                 --specs[cnt].info.width;
 472
 473               if (!specs[cnt].info.left && specs[cnt].info.pad == ' ')
 474                 PAD (' ');
 475
 476               if (is_neg)
 477                 outchar ('-');
 478               else if (specs[cnt].info.showsign)
 479                 outchar ('+');
 480               else if (specs[cnt].info.space)
 481                 outchar (' ');
 482
 483               if (num != 0 && specs[cnt].info.alt && base == 16)
 484                 {
 485                   outchar ('0');
 486                   outchar (specs[cnt].info.spec);
 487                 }
 488
 489               if (!specs[cnt].info.left && specs[cnt].info.pad == '0')
 490                 PAD ('0');
 491
 492               /* Write the number.  */
 493               while (++w <= workend)
 494                 outchar (*w);
 495
 496               if (specs[cnt].info.left)
 497                 PAD (' ');
 498             }
 499             break;
 500
 501           case 'e':
 502           case 'E':
 503           case 'f':
 504           case 'g':
 505           case 'G':
 506             {
 507               /* Floating-point number.  This is handled by printf_fp.c.  */
 508               extern printf_function __printf_fp;
 509               function = __printf_fp;
 510               goto use_function;
 511             }
 512
 513           case 'c':
 514             /* Character.  */
 515             --specs[cnt].info.width;/* Account for the character itself.  */
 516             if (!specs[cnt].info.left)
 517               PAD (' ');
 518             outchar ((unsigned char) args_value[specs[cnt].data_arg].pa_char);
 519             if (specs[cnt].info.left)
 520               PAD (' ');
 521             break;
 522
 523           case 's':
 524             {
 525               static const char null[] = "(null)";
 526               size_t len;
 527
 528               str = args_value[specs[cnt].data_arg].pa_string;
 529
 530             string:
 531
 532               if (str == NULL)
 533                 {
 534                   /* Write "(null)" if there's space.  */
 535                   if (specs[cnt].info.prec == -1
 536                       || specs[cnt].info.prec >= (int) sizeof (null) - 1)
 537                     {
 538                       str = null;
 539                       len = sizeof (null) - 1;
 540                     }
 541                   else
 542                     {
 543                       str = "";
 544                       len = 0;
 545                     }
 546                 }
 547               else if (specs[cnt].info.prec != -1)
 548                 {
 549                   /* Search for the end of the string, but don't search
 550                      past the length specified by the precision.  */
 551                   const char *end = memchr (str, '\0', specs[cnt].info.prec);
 552                   if (end)
 553                     len = end - str;
 554                   else
 555                     len = specs[cnt].info.prec;
 556                 }
 557               else
 558                 len = strlen (str);
 559
 560               specs[cnt].info.width -= len;
 561
 562               if (!specs[cnt].info.left)
 563                 PAD (' ');
 564               outstring (str, len);
 565               if (specs[cnt].info.left)
 566                 PAD (' ');
 567             }
 568             break;
 569
 570           case 'p':
 571             /* Generic pointer.  */
 572             {
 573               const void *ptr;
 574               ptr = args_value[specs[cnt].data_arg].pa_pointer;
 575               if (ptr != NULL)
 576                 {
 577                   /* If the pointer is not NULL, write it as a %#x spec.  */
 578                   base = 16;
 579                   num = (unsigned long long int) (unsigned long int) ptr;
 580                   is_neg = 0;
 581                   specs[cnt].info.alt = 1;
 582                   specs[cnt].info.spec = 'x';
 583                   specs[cnt].info.group = 0;
 584                   goto number;
 585                 }
 586               else
 587                 {
 588                   /* Write "(nil)" for a nil pointer.  */
 589                   str = "(nil)";
 590                   /* Make sure the full string "(nil)" is printed.  */
 591                   if (specs[cnt].info.prec < 5)
 592                     specs[cnt].info.prec = 5;
 593                   goto string;
 594                 }
 595             }
 596             break;
 597
 598           case 'n':
 599             /* Answer the count of characters written.  */
 600             if (specs[cnt].info.is_longlong)
 601               *(long long int *)
 602                 args_value[specs[cnt].data_arg].pa_pointer = done;
 603             else if (specs[cnt].info.is_long)
 604               *(long int *)
 605                 args_value[specs[cnt].data_arg].pa_pointer = done;
 606             else if (!specs[cnt].info.is_short)
 607               *(int *)
 608                 args_value[specs[cnt].data_arg].pa_pointer = done;
 609             else
 610               *(short int *)
 611                 args_value[specs[cnt].data_arg].pa_pointer = done;
 612             break;
 613
 614           case 'm':
 615             {
 616               extern char *_strerror_internal __P ((int, char *buf, size_t));
 617               str = _strerror_internal (errno, errorbuf, sizeof errorbuf);
 618               goto string;
 619             }
 620
 621           default:
 622             /* Unrecognized format specifier.  */
 623             function = printf_unknown;
 624             goto use_function;
 625           }
 626
 627       /* Write the following constant string.  */
 628       outstring (specs[cnt].end_of_fmt,
 629                  specs[cnt].next_fmt - specs[cnt].end_of_fmt);
 630     }
 631
 632   return done;
 633 }
 634
 635 #ifdef USE_IN_LIBIO
 636 # undef vfprintf
 637 # ifdef strong_alias
 638 /* This is for glibc.  */
 639 strong_alias (_IO_vfprintf, vfprintf)
 640 # else
 641 #  if defined __ELF__ || defined __GNU_LIBRARY__
 642 #   include <gnu-stabs.h>
 643 #   ifdef weak_alias
 644 weak_alias (_IO_vfprintf, vfprintf);
 645 #   endif
 646 #  endif
 647 # endif
 648 #endif
 649
 650
 651 /* Handle an unknown format specifier.  This prints out a canonicalized
 652    representation of the format spec itself.  */
 653
 654 static int
 655 printf_unknown (s, info, args)
 656   FILE *s;
 657   const struct printf_info *info;
 658   const void **const args;
 659 {
 660   int done = 0;
 661   char work[BUFSIZ];
 662   char *const workend = &work[sizeof(work) - 1];
 663   register char *w;
 664
 665   outchar ('%');
 666
 667   if (info->alt)
 668     outchar ('#');
 669   if (info->group)
 670     outchar ('\'');
 671   if (info->showsign)
 672     outchar ('+');
 673   else if (info->space)
 674     outchar (' ');
 675   if (info->left)
 676     outchar ('-');
 677   if (info->pad == '0')
 678     outchar ('0');
 679
 680   if (info->width != 0)
 681     {
 682       w = _itoa (info->width, workend + 1, 10, 0);
 683       while (++w <= workend)
 684         outchar (*w);
 685     }
 686
 687   if (info->prec != -1)
 688     {
 689       outchar ('.');
 690       w = _itoa (info->prec, workend + 1, 10, 0);
 691       while (++w <= workend)
 692         outchar (*w);
 693     }
 694
 695   if (info->spec != '\0')
 696     outchar (info->spec);
 697
 698   return done;
 699 }
 700 \f
 701 /* Group the digits according to the grouping rules of the current locale.
 702    The interpretation of GROUPING is as in `struct lconv' from <locale.h>.  */
 703
 704 static char *
 705 group_number (char *w, char *workend, const char *grouping,
 706               wchar_t thousands_sep)
 707 {
 708   int len;
 709   char *src, *s;
 710
 711   /* We treat all negative values like CHAR_MAX.  */
 712
 713   if (*grouping == CHAR_MAX || *grouping < 0)
 714     /* No grouping should be done.  */
 715     return w;
 716
 717   len = *grouping;
 718
 719   /* Copy existing string so that nothing gets overwritten.  */
 720   src = (char *) alloca (workend - w);
 721   memcpy (src, w + 1, workend - w);
 722   s = &src[workend - w - 1];
 723   w = workend;
 724
 725   /* Process all characters in the string.  */
 726   while (s >= src)
 727     {
 728       *w-- = *s--;
 729
 730       if (--len == 0 && s >= src)
 731         {
 732           /* A new group begins.  */
 733           *w-- = thousands_sep;
 734
 735           len = *grouping++;
 736           if (*grouping == '\0')
 737             /* The previous grouping repeats ad infinitum.  */
 738             --grouping;
 739           else if (*grouping == CHAR_MAX || *grouping < 0)
 740             {
 741               /* No further grouping to be done.
 742                  Copy the rest of the number.  */
 743               do
 744                 *w-- = *s--;
 745               while (s >= src);
 746               break;
 747             }
 748         }
 749     }
 750   return w;
 751 }
 752 \f
 753 #ifdef USE_IN_LIBIO
 754 /* Helper "class" for `fprintf to unbuffered': creates a temporary buffer.  */
 755 struct helper_file
 756   {
 757     struct _IO_FILE_plus _f;
 758     _IO_FILE *_put_stream;
 759   };
 760
 761 static int
 762 _IO_helper_overflow (_IO_FILE *s, int c)
 763 {
 764   _IO_FILE *target = ((struct helper_file*) s)->_put_stream;
 765   int used = s->_IO_write_ptr - s->_IO_write_base;
 766   if (used)
 767     {
 768       _IO_size_t written = _IO_sputn (target, s->_IO_write_base, used);
 769       s->_IO_write_ptr -= written;
 770     }
 771   return _IO_putc (c, s);
 772 }
 773
 774 static const struct _IO_jump_t _IO_helper_jumps =
 775   {
 776     JUMP_INIT_DUMMY,
 777     JUMP_INIT (finish, _IO_default_finish),
 778     JUMP_INIT (overflow, _IO_helper_overflow),
 779     JUMP_INIT (underflow, _IO_default_underflow),
 780     JUMP_INIT (uflow, _IO_default_uflow),
 781     JUMP_INIT (pbackfail, _IO_default_pbackfail),
 782     JUMP_INIT (xsputn, _IO_default_xsputn),
 783     JUMP_INIT (xsgetn, _IO_default_xsgetn),
 784     JUMP_INIT (seekoff, _IO_default_seekoff),
 785     JUMP_INIT (seekpos, _IO_default_seekpos),
 786     JUMP_INIT (setbuf, _IO_default_setbuf),
 787     JUMP_INIT (sync, _IO_default_sync),
 788     JUMP_INIT (doallocate, _IO_default_doallocate),
 789     JUMP_INIT (read, _IO_default_read),
 790     JUMP_INIT (write, _IO_default_write),
 791     JUMP_INIT (seek, _IO_default_seek),
 792     JUMP_INIT (close, _IO_default_close),
 793     JUMP_INIT (stat, _IO_default_stat)
 794   };
 795
 796 static int
 797 buffered_vfprintf (s, format, args)
 798   register _IO_FILE *s;
 799   char const *format;
 800   _IO_va_list args;
 801 {
 802   char buf[_IO_BUFSIZ];
 803   struct helper_file helper;
 804   register _IO_FILE *hp = (_IO_FILE *) &helper;
 805   int result, to_flush;
 806
 807   /* Initialize helper.  */
 808   helper._put_stream = s;
 809   hp->_IO_write_base = buf;
 810   hp->_IO_write_ptr = buf;
 811   hp->_IO_write_end = buf + sizeof buf;
 812   hp->_IO_file_flags = _IO_MAGIC|_IO_NO_READS;
 813   _IO_JUMPS (hp) = (struct _IO_jump_t *) &_IO_helper_jumps;
 814
 815   /* Now print to helper instead.  */
 816   result = _IO_vfprintf (hp, format, args);
 817
 818   /* Now flush anything from the helper to the S. */
 819   if ((to_flush = hp->_IO_write_ptr - hp->_IO_write_base) > 0)
 820     {
 821       if (_IO_sputn (s, hp->_IO_write_base, to_flush) != to_flush)
 822         return -1;
 823     }
 824
 825   return result;
 826 }
 827
 828 #else /* !USE_IN_LIBIO */
 829
 830 static int
 831 buffered_vfprintf (s, format, args)
 832   register FILE *s;
 833   char const *format;
 834   va_list args;
 835 {
 836   char buf[BUFSIZ];
 837   int result;
 838
 839   s->__bufp = s->__buffer = buf;
 840   s->__bufsize = sizeof buf;
 841   s->__put_limit = s->__buffer + s->__bufsize;
 842   s->__get_limit = s->__buffer;
 843
 844   /* Now use buffer to print.  */
 845   result = vfprintf (s, format, args);
 846
 847   if (fflush (s) == EOF)
 848     result = -1;
 849   s->__buffer = s->__bufp = s->__get_limit = s->__put_limit = NULL;
 850   s->__bufsize = 0;
 851
 852   return result;
 853 }
 854
 855
 856 /* Pads string with given number of a specified character.
 857    This code is taken from iopadn.c of the GNU I/O library.  */
 858 #define PADSIZE 16
 859 static const char blanks[PADSIZE] =
 860 {' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' ',' '};
 861 static const char zeroes[PADSIZE] =
 862 {'0','0','0','0','0','0','0','0','0','0','0','0','0','0','0','0'};
 863
 864 ssize_t
 865 __printf_pad (s, pad, count)
 866      FILE *s;
 867      char pad;
 868      size_t count;
 869 {
 870   const char *padptr;
 871   register size_t i;
 872
 873   padptr = pad == ' ' ? blanks : zeroes;
 874
 875   for (i = count; i >= PADSIZE; i -= PADSIZE)
 876     if (PUT (s, padptr, PADSIZE) != PADSIZE)
 877       return -1;
 878   if (i > 0)
 879     if (PUT (s, padptr, i) != i)
 880       return -1;
 881
 882   return count;
 883 }
 884 #undef PADSIZE
 885 #endif /* USE_IN_LIBIO */