src/doprnt.c

   1 /* Output like sprintf to a buffer of specified size.
   2    Also takes args differently: pass one pointer to an array of strings
   3    in addition to the format string which is separate.
   4    Copyright (C) 1985, 2001, 2002, 2003, 2004, 2005,
   5                  2006, 2007, 2008  Free Software Foundation, Inc.
   6
   7 This file is part of GNU Emacs.
   8
   9 GNU Emacs is free software: you can redistribute it and/or modify
  10 it under the terms of the GNU General Public License as published by
  11 the Free Software Foundation, either version 3 of the License, or
  12 (at your option) any later version.
  13
  14 GNU Emacs is distributed in the hope that it will be useful,
  15 but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 GNU General Public License for more details.
  18
  19 You should have received a copy of the GNU General Public License
  20 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22
  23 #include <config.h>
  24 #include <stdio.h>
  25 #include <ctype.h>
  26
  27 #ifdef STDC_HEADERS
  28 #include <float.h>
  29 #endif
  30
  31 #ifdef HAVE_UNISTD_H
  32 #include <unistd.h>
  33 #endif
  34
  35 #ifdef HAVE_STDLIB_H
  36 #include <stdlib.h>
  37 #endif
  38
  39 #include "lisp.h"
  40
  41 #ifndef DBL_MAX_10_EXP
  42 #define DBL_MAX_10_EXP 308 /* IEEE double */
  43 #endif
  44
  45 /* Since we use the macro CHAR_HEAD_P, we have to include this, but
  46    don't have to include others because CHAR_HEAD_P does not contains
  47    another macro.  */
  48 #include "character.h"
  49
  50 static int doprnt1 ();
  51
  52 /* Generate output from a format-spec FORMAT,
  53    terminated at position FORMAT_END.
  54    Output goes in BUFFER, which has room for BUFSIZE chars.
  55    If the output does not fit, truncate it to fit.
  56    Returns the number of bytes stored into BUFFER.
  57    ARGS points to the vector of arguments, and NARGS says how many.
  58    A double counts as two arguments.
  59    String arguments are passed as C strings.
  60    Integers are passed as C integers.  */
  61
  62 int
  63 doprnt (buffer, bufsize, format, format_end, nargs, args)
  64      char *buffer;
  65      register int bufsize;
  66      char *format;
  67      char *format_end;
  68      int nargs;
  69      char **args;
  70 {
  71   return doprnt1 (0, buffer, bufsize, format, format_end, nargs, args);
  72 }
  73
  74 /* Like doprnt except that strings in ARGS are passed
  75    as Lisp_Object.  */
  76
  77 int
  78 doprnt_lisp (buffer, bufsize, format, format_end, nargs, args)
  79      char *buffer;
  80      register int bufsize;
  81      char *format;
  82      char *format_end;
  83      int nargs;
  84      char **args;
  85 {
  86   return doprnt1 (1, buffer, bufsize, format, format_end, nargs, args);
  87 }
  88
  89 static int
  90 doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
  91      int lispstrings;
  92      char *buffer;
  93      register int bufsize;
  94      char *format;
  95      char *format_end;
  96      int nargs;
  97      char **args;
  98 {
  99   int cnt = 0;                  /* Number of arg to gobble next */
 100   register char *fmt = format;  /* Pointer into format string */
 101   register char *bufptr = buffer; /* Pointer into output buffer.. */
 102
 103   /* Use this for sprintf unless we need something really big.  */
 104   char tembuf[DBL_MAX_10_EXP + 100];
 105
 106   /* Size of sprintf_buffer.  */
 107   unsigned size_allocated = sizeof (tembuf);
 108
 109   /* Buffer to use for sprintf.  Either tembuf or same as BIG_BUFFER.  */
 110   char *sprintf_buffer = tembuf;
 111
 112   /* Buffer we have got with malloc.  */
 113   char *big_buffer = 0;
 114
 115   register int tem;
 116   unsigned char *string;
 117   char fixed_buffer[20];        /* Default buffer for small formatting. */
 118   char *fmtcpy;
 119   int minlen;
 120   unsigned char charbuf[5];     /* Used for %c.  */
 121
 122   if (format_end == 0)
 123     format_end = format + strlen (format);
 124
 125   if ((format_end - format + 1) < sizeof (fixed_buffer))
 126     fmtcpy = fixed_buffer;
 127   else
 128     fmtcpy = (char *) alloca (format_end - format + 1);
 129
 130   bufsize--;
 131
 132   /* Loop until end of format string or buffer full. */
 133   while (fmt != format_end && bufsize > 0)
 134     {
 135       if (*fmt == '%')  /* Check for a '%' character */
 136         {
 137           unsigned size_bound = 0;
 138           int width;            /* Columns occupied by STRING.  */
 139
 140           fmt++;
 141           /* Copy this one %-spec into fmtcpy.  */
 142           string = (unsigned char *) fmtcpy;
 143           *string++ = '%';
 144           while (1)
 145             {
 146               *string++ = *fmt;
 147               if ('0' <= *fmt && *fmt <= '9')
 148                 {
 149                   /* Get an idea of how much space we might need.
 150                      This might be a field width or a precision; e.g.
 151                      %1.1000f and %1000.1f both might need 1000+ bytes.
 152                      Parse the width or precision, checking for overflow.  */
 153                   unsigned n = *fmt - '0';
 154                   while ('0' <= fmt[1] && fmt[1] <= '9')
 155                     {
 156                       if (n * 10 / 10 != n
 157                           || (n = n * 10 + (fmt[1] - '0')) < n)
 158                         error ("Format width or precision too large");
 159                       *string++ = *++fmt;
 160                     }
 161
 162                   if (size_bound < n)
 163                     size_bound = n;
 164                 }
 165               else if (*fmt == '-' || *fmt == ' ' || *fmt == '.' || *fmt == '+')
 166                 ;
 167               else
 168                 break;
 169               fmt++;
 170             }
 171           *string = 0;
 172
 173           /* Make the size bound large enough to handle floating point formats
 174              with large numbers.  */
 175           if (size_bound + DBL_MAX_10_EXP + 50 < size_bound)
 176             error ("Format width or precision too large");
 177           size_bound += DBL_MAX_10_EXP + 50;
 178
 179           /* Make sure we have that much.  */
 180           if (size_bound > size_allocated)
 181             {
 182               if (big_buffer)
 183                 big_buffer = (char *) xrealloc (big_buffer, size_bound);
 184               else
 185                 big_buffer = (char *) xmalloc (size_bound);
 186               sprintf_buffer = big_buffer;
 187               size_allocated = size_bound;
 188             }
 189           minlen = 0;
 190           switch (*fmt++)
 191             {
 192             default:
 193               error ("Invalid format operation %%%c", fmt[-1]);
 194
 195 /*          case 'b': */
 196             case 'd':
 197             case 'o':
 198             case 'x':
 199               if (cnt == nargs)
 200                 error ("Not enough arguments for format string");
 201               if (sizeof (int) == sizeof (EMACS_INT))
 202                 ;
 203               else if (sizeof (long) == sizeof (EMACS_INT))
 204                 /* Insert an `l' the right place.  */
 205                 string[1] = string[0],
 206                 string[0] = string[-1],
 207                 string[-1] = 'l',
 208                 string++;
 209               else
 210                 abort ();
 211               sprintf (sprintf_buffer, fmtcpy, args[cnt++]);
 212               /* Now copy into final output, truncating as nec.  */
 213               string = (unsigned char *) sprintf_buffer;
 214               goto doit;
 215
 216             case 'f':
 217             case 'e':
 218             case 'g':
 219               {
 220                 union { double d; char *half[2]; } u;
 221                 if (cnt + 1 == nargs)
 222                   error ("Not enough arguments for format string");
 223                 u.half[0] = args[cnt++];
 224                 u.half[1] = args[cnt++];
 225                 sprintf (sprintf_buffer, fmtcpy, u.d);
 226                 /* Now copy into final output, truncating as nec.  */
 227                 string = (unsigned char *) sprintf_buffer;
 228                 goto doit;
 229               }
 230
 231             case 'S':
 232               string[-1] = 's';
 233             case 's':
 234               if (cnt == nargs)
 235                 error ("Not enough arguments for format string");
 236               if (fmtcpy[1] != 's')
 237                 minlen = atoi (&fmtcpy[1]);
 238               if (lispstrings)
 239                 {
 240                   string = ((struct Lisp_String *) args[cnt])->data;
 241                   tem = STRING_BYTES ((struct Lisp_String *) args[cnt]);
 242                   cnt++;
 243                 }
 244               else
 245                 {
 246                   string = (unsigned char *) args[cnt++];
 247                   tem = strlen (string);
 248                 }
 249               width = strwidth (string, tem);
 250               goto doit1;
 251
 252               /* Copy string into final output, truncating if no room.  */
 253             doit:
 254               /* Coming here means STRING contains ASCII only.  */
 255               width = tem = strlen (string);
 256             doit1:
 257               /* We have already calculated:
 258                  TEM -- length of STRING,
 259                  WIDTH -- columns occupied by STRING when displayed, and
 260                  MINLEN -- minimum columns of the output.  */
 261               if (minlen > 0)
 262                 {
 263                   while (minlen > width && bufsize > 0)
 264                     {
 265                       *bufptr++ = ' ';
 266                       bufsize--;
 267                       minlen--;
 268                     }
 269                   minlen = 0;
 270                 }
 271               if (tem > bufsize)
 272                 {
 273                   /* Truncate the string at character boundary.  */
 274                   tem = bufsize;
 275                   while (!CHAR_HEAD_P (string[tem - 1])) tem--;
 276                   bcopy (string, bufptr, tem);
 277                   /* We must calculate WIDTH again.  */
 278                   width = strwidth (bufptr, tem);
 279                 }
 280               else
 281                 bcopy (string, bufptr, tem);
 282               bufptr += tem;
 283               bufsize -= tem;
 284               if (minlen < 0)
 285                 {
 286                   while (minlen < - width && bufsize > 0)
 287                     {
 288                       *bufptr++ = ' ';
 289                       bufsize--;
 290                       minlen++;
 291                     }
 292                   minlen = 0;
 293                 }
 294               continue;
 295
 296             case 'c':
 297               if (cnt == nargs)
 298                 error ("Not enough arguments for format string");
 299               tem = CHAR_STRING ((int) (EMACS_INT) args[cnt], charbuf);
 300               string = charbuf;
 301               cnt++;
 302               string[tem] = 0;
 303               width = strwidth (string, tem);
 304               if (fmtcpy[1] != 'c')
 305                 minlen = atoi (&fmtcpy[1]);
 306               goto doit1;
 307
 308             case '%':
 309               fmt--;    /* Drop thru and this % will be treated as normal */
 310             }
 311         }
 312
 313       {
 314         /* Just some character; Copy it if the whole multi-byte form
 315            fit in the buffer.  */
 316         char *save_bufptr = bufptr;
 317
 318         do { *bufptr++ = *fmt++; }
 319         while (--bufsize > 0 && !CHAR_HEAD_P (*fmt));
 320         if (!CHAR_HEAD_P (*fmt))
 321           {
 322             bufptr = save_bufptr;
 323             break;
 324           }
 325       }
 326     };
 327
 328   /* If we had to malloc something, free it.  */
 329   xfree (big_buffer);
 330
 331   *bufptr = 0;          /* Make sure our string end with a '\0' */
 332   return bufptr - buffer;
 333 }
 334
 335 /* arch-tag: aa0ab528-7c5f-4c73-894c-aa2526a1efb3
 336    (do not change this comment) */