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  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, or (at your option)
  12 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; see the file COPYING.  If not, write to
  21 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22 Boston, MA 02110-1301, USA.  */
  23
  24
  25 #include <config.h>
  26 #include <stdio.h>
  27 #include <ctype.h>
  28
  29 #ifdef STDC_HEADERS
  30 #include <float.h>
  31 #endif
  32
  33 #ifdef HAVE_UNISTD_H
  34 #include <unistd.h>
  35 #endif
  36
  37 #ifdef HAVE_STDLIB_H
  38 #include <stdlib.h>
  39 #endif
  40
  41 #include "lisp.h"
  42
  43 #ifndef DBL_MAX_10_EXP
  44 #define DBL_MAX_10_EXP 308 /* IEEE double */
  45 #endif
  46
  47 /* Since we use the macro CHAR_HEAD_P, we have to include this, but
  48    don't have to include others because CHAR_HEAD_P does not contains
  49    another macro.  */
  50 #include "charset.h"
  51
  52 static int doprnt1 ();
  53
  54 /* Generate output from a format-spec FORMAT,
  55    terminated at position FORMAT_END.
  56    Output goes in BUFFER, which has room for BUFSIZE chars.
  57    If the output does not fit, truncate it to fit.
  58    Returns the number of bytes stored into BUFFER.
  59    ARGS points to the vector of arguments, and NARGS says how many.
  60    A double counts as two arguments.
  61    String arguments are passed as C strings.
  62    Integers are passed as C integers.  */
  63
  64 int
  65 doprnt (buffer, bufsize, format, format_end, nargs, args)
  66      char *buffer;
  67      register int bufsize;
  68      char *format;
  69      char *format_end;
  70      int nargs;
  71      char **args;
  72 {
  73   return doprnt1 (0, buffer, bufsize, format, format_end, nargs, args);
  74 }
  75
  76 /* Like doprnt except that strings in ARGS are passed
  77    as Lisp_Object.  */
  78
  79 int
  80 doprnt_lisp (buffer, bufsize, format, format_end, nargs, args)
  81      char *buffer;
  82      register int bufsize;
  83      char *format;
  84      char *format_end;
  85      int nargs;
  86      char **args;
  87 {
  88   return doprnt1 (1, buffer, bufsize, format, format_end, nargs, args);
  89 }
  90
  91 static int
  92 doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
  93      int lispstrings;
  94      char *buffer;
  95      register int bufsize;
  96      char *format;
  97      char *format_end;
  98      int nargs;
  99      char **args;
 100 {
 101   int cnt = 0;                  /* Number of arg to gobble next */
 102   register char *fmt = format;  /* Pointer into format string */
 103   register char *bufptr = buffer; /* Pointer into output buffer.. */
 104
 105   /* Use this for sprintf unless we need something really big.  */
 106   char tembuf[DBL_MAX_10_EXP + 100];
 107
 108   /* Size of sprintf_buffer.  */
 109   unsigned size_allocated = sizeof (tembuf);
 110
 111   /* Buffer to use for sprintf.  Either tembuf or same as BIG_BUFFER.  */
 112   char *sprintf_buffer = tembuf;
 113
 114   /* Buffer we have got with malloc.  */
 115   char *big_buffer = 0;
 116
 117   register int tem;
 118   unsigned char *string;
 119   char fixed_buffer[20];        /* Default buffer for small formatting. */
 120   char *fmtcpy;
 121   int minlen;
 122   unsigned char charbuf[5];     /* Used for %c.  */
 123
 124   if (format_end == 0)
 125     format_end = format + strlen (format);
 126
 127   if ((format_end - format + 1) < sizeof (fixed_buffer))
 128     fmtcpy = fixed_buffer;
 129   else
 130     fmtcpy = (char *) alloca (format_end - format + 1);
 131
 132   bufsize--;
 133
 134   /* Loop until end of format string or buffer full. */
 135   while (fmt != format_end && bufsize > 0)
 136     {
 137       if (*fmt == '%')  /* Check for a '%' character */
 138         {
 139           unsigned size_bound = 0;
 140           int width;            /* Columns occupied by STRING.  */
 141
 142           fmt++;
 143           /* Copy this one %-spec into fmtcpy.  */
 144           string = (unsigned char *) fmtcpy;
 145           *string++ = '%';
 146           while (1)
 147             {
 148               *string++ = *fmt;
 149               if ('0' <= *fmt && *fmt <= '9')
 150                 {
 151                   /* Get an idea of how much space we might need.
 152                      This might be a field width or a precision; e.g.
 153                      %1.1000f and %1000.1f both might need 1000+ bytes.
 154                      Parse the width or precision, checking for overflow.  */
 155                   unsigned n = *fmt - '0';
 156                   while ('0' <= fmt[1] && fmt[1] <= '9')
 157                     {
 158                       if (n * 10 / 10 != n
 159                           || (n = n * 10 + (fmt[1] - '0')) < n)
 160                         error ("Format width or precision too large");
 161                       *string++ = *++fmt;
 162                     }
 163
 164                   if (size_bound < n)
 165                     size_bound = n;
 166                 }
 167               else if (*fmt == '-' || *fmt == ' ' || *fmt == '.' || *fmt == '+')
 168                 ;
 169               else
 170                 break;
 171               fmt++;
 172             }
 173           *string = 0;
 174
 175           /* Make the size bound large enough to handle floating point formats
 176              with large numbers.  */
 177           if (size_bound + DBL_MAX_10_EXP + 50 < size_bound)
 178             error ("Format width or precision too large");
 179           size_bound += DBL_MAX_10_EXP + 50;
 180
 181           /* Make sure we have that much.  */
 182           if (size_bound > size_allocated)
 183             {
 184               if (big_buffer)
 185                 big_buffer = (char *) xrealloc (big_buffer, size_bound);
 186               else
 187                 big_buffer = (char *) xmalloc (size_bound);
 188               sprintf_buffer = big_buffer;
 189               size_allocated = size_bound;
 190             }
 191           minlen = 0;
 192           switch (*fmt++)
 193             {
 194             default:
 195               error ("Invalid format operation %%%c", fmt[-1]);
 196
 197 /*          case 'b': */
 198             case 'd':
 199             case 'o':
 200             case 'x':
 201               if (cnt == nargs)
 202                 error ("Not enough arguments for format string");
 203               if (sizeof (int) == sizeof (EMACS_INT))
 204                 ;
 205               else if (sizeof (long) == sizeof (EMACS_INT))
 206                 /* Insert an `l' the right place.  */
 207                 string[1] = string[0],
 208                 string[0] = string[-1],
 209                 string[-1] = 'l',
 210                 string++;
 211               else
 212                 abort ();
 213               sprintf (sprintf_buffer, fmtcpy, args[cnt++]);
 214               /* Now copy into final output, truncating as nec.  */
 215               string = (unsigned char *) sprintf_buffer;
 216               goto doit;
 217
 218             case 'f':
 219             case 'e':
 220             case 'g':
 221               {
 222                 union { double d; char *half[2]; } u;
 223                 if (cnt + 1 == nargs)
 224                   error ("Not enough arguments for format string");
 225                 u.half[0] = args[cnt++];
 226                 u.half[1] = args[cnt++];
 227                 sprintf (sprintf_buffer, fmtcpy, u.d);
 228                 /* Now copy into final output, truncating as nec.  */
 229                 string = (unsigned char *) sprintf_buffer;
 230                 goto doit;
 231               }
 232
 233             case 'S':
 234               string[-1] = 's';
 235             case 's':
 236               if (cnt == nargs)
 237                 error ("Not enough arguments for format string");
 238               if (fmtcpy[1] != 's')
 239                 minlen = atoi (&fmtcpy[1]);
 240               if (lispstrings)
 241                 {
 242                   string = ((struct Lisp_String *) args[cnt])->data;
 243                   tem = STRING_BYTES ((struct Lisp_String *) args[cnt]);
 244                   cnt++;
 245                 }
 246               else
 247                 {
 248                   string = (unsigned char *) args[cnt++];
 249                   tem = strlen (string);
 250                 }
 251               width = strwidth (string, tem);
 252               goto doit1;
 253
 254               /* Copy string into final output, truncating if no room.  */
 255             doit:
 256               /* Coming here means STRING contains ASCII only.  */
 257               width = tem = strlen (string);
 258             doit1:
 259               /* We have already calculated:
 260                  TEM -- length of STRING,
 261                  WIDTH -- columns occupied by STRING when displayed, and
 262                  MINLEN -- minimum columns of the output.  */
 263               if (minlen > 0)
 264                 {
 265                   while (minlen > width && bufsize > 0)
 266                     {
 267                       *bufptr++ = ' ';
 268                       bufsize--;
 269                       minlen--;
 270                     }
 271                   minlen = 0;
 272                 }
 273               if (tem > bufsize)
 274                 {
 275                   /* Truncate the string at character boundary.  */
 276                   tem = bufsize;
 277                   while (!CHAR_HEAD_P (string[tem - 1])) tem--;
 278                   bcopy (string, bufptr, tem);
 279                   /* We must calculate WIDTH again.  */
 280                   width = strwidth (bufptr, tem);
 281                 }
 282               else
 283                 bcopy (string, bufptr, tem);
 284               bufptr += tem;
 285               bufsize -= tem;
 286               if (minlen < 0)
 287                 {
 288                   while (minlen < - width && bufsize > 0)
 289                     {
 290                       *bufptr++ = ' ';
 291                       bufsize--;
 292                       minlen++;
 293                     }
 294                   minlen = 0;
 295                 }
 296               continue;
 297
 298             case 'c':
 299               if (cnt == nargs)
 300                 error ("Not enough arguments for format string");
 301               tem = CHAR_STRING ((int) (EMACS_INT) args[cnt], charbuf);
 302               string = charbuf;
 303               cnt++;
 304               string[tem] = 0;
 305               width = strwidth (string, tem);
 306               if (fmtcpy[1] != 'c')
 307                 minlen = atoi (&fmtcpy[1]);
 308               goto doit1;
 309
 310             case '%':
 311               fmt--;    /* Drop thru and this % will be treated as normal */
 312             }
 313         }
 314
 315       {
 316         /* Just some character; Copy it if the whole multi-byte form
 317            fit in the buffer.  */
 318         char *save_bufptr = bufptr;
 319
 320         do { *bufptr++ = *fmt++; }
 321         while (--bufsize > 0 && !CHAR_HEAD_P (*fmt));
 322         if (!CHAR_HEAD_P (*fmt))
 323           {
 324             bufptr = save_bufptr;
 325             break;
 326           }
 327       }
 328     };
 329
 330   /* If we had to malloc something, free it.  */
 331   if (big_buffer)
 332     xfree (big_buffer);
 333
 334   *bufptr = 0;          /* Make sure our string end with a '\0' */
 335   return bufptr - buffer;
 336 }
 337
 338 /* arch-tag: aa0ab528-7c5f-4c73-894c-aa2526a1efb3
 339    (do not change this comment) */