code.delx.au - gnu-emacs/blob - 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 Free Software Foundation, Inc.
   5
   6 This file is part of GNU Emacs.
   7
   8 GNU Emacs is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2, or (at your option)
  11 any later version.
  12
  13 GNU Emacs is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Emacs; see the file COPYING.  If not, write to
  20 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  21 Boston, MA 02111-1307, USA.  */
  22
  23
  24 #include <config.h>
  25 #include <stdio.h>
  26 #include <ctype.h>
  27
  28 #ifdef STDC_HEADERS
  29 #include <float.h>
  30 #endif
  31
  32 #include "lisp.h"
  33
  34 #ifndef DBL_MAX_10_EXP
  35 #define DBL_MAX_10_EXP 308 /* IEEE double */
  36 #endif
  37
  38 /* Since we use the macro CHAR_HEAD_P, we have to include this, but
  39    don't have to include others because CHAR_HEAD_P does not contains
  40    another macro.  */
  41 #include "charset.h"
  42
  43 extern long *xmalloc (), *xrealloc ();
  44
  45 static int doprnt1 ();
  46
  47 /* Generate output from a format-spec FORMAT,
  48    terminated at position FORMAT_END.
  49    Output goes in BUFFER, which has room for BUFSIZE chars.
  50    If the output does not fit, truncate it to fit.
  51    Returns the number of characters stored into BUFFER.
  52    ARGS points to the vector of arguments, and NARGS says how many.
  53    A double counts as two arguments.
  54    String arguments are passed as C strings.
  55    Integers are passed as C integers.  */
  56
  57 int
  58 doprnt (buffer, bufsize, format, format_end, nargs, args)
  59      char *buffer;
  60      register int bufsize;
  61      char *format;
  62      char *format_end;
  63      int nargs;
  64      char **args;
  65 {
  66   return doprnt1 (0, buffer, bufsize, format, format_end, nargs, args);
  67 }
  68
  69 /* Like doprnt except that strings in ARGS are passed
  70    as Lisp_Object.  */
  71
  72 int
  73 doprnt_lisp (buffer, bufsize, format, format_end, nargs, args)
  74      char *buffer;
  75      register int bufsize;
  76      char *format;
  77      char *format_end;
  78      int nargs;
  79      char **args;
  80 {
  81   return doprnt1 (1, buffer, bufsize, format, format_end, nargs, args);
  82 }
  83
  84 static int
  85 doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
  86      int lispstrings;
  87      char *buffer;
  88      register int bufsize;
  89      char *format;
  90      char *format_end;
  91      int nargs;
  92      char **args;
  93 {
  94   int cnt = 0;                  /* Number of arg to gobble next */
  95   register char *fmt = format;  /* Pointer into format string */
  96   register char *bufptr = buffer; /* Pointer into output buffer.. */
  97
  98   /* Use this for sprintf unless we need something really big.  */
  99   char tembuf[DBL_MAX_10_EXP + 100];
 100
 101   /* Size of sprintf_buffer.  */
 102   int size_allocated = sizeof (tembuf);
 103
 104   /* Buffer to use for sprintf.  Either tembuf or same as BIG_BUFFER.  */
 105   char *sprintf_buffer = tembuf;
 106
 107   /* Buffer we have got with malloc.  */
 108   char *big_buffer = 0;
 109
 110   register int tem;
 111   char *string;
 112   char fixed_buffer[20];        /* Default buffer for small formatting. */
 113   char *fmtcpy;
 114   int minlen;
 115   int size;                     /* Field width factor; e.g., %90d */
 116   unsigned char charbuf[5];     /* Used for %c.  */
 117
 118   if (format_end == 0)
 119     format_end = format + strlen (format);
 120
 121   if ((format_end - format + 1) < sizeof (fixed_buffer))
 122     fmtcpy = fixed_buffer;
 123   else
 124     fmtcpy = (char *) alloca (format_end - format + 1);
 125
 126   bufsize--;
 127
 128   /* Loop until end of format string or buffer full. */
 129   while (fmt != format_end && bufsize > 0)
 130     {
 131       if (*fmt == '%')  /* Check for a '%' character */
 132         {
 133           int size_bound = 0;
 134           int width;            /* Columns occupied by STRING.  */
 135
 136           fmt++;
 137           /* Copy this one %-spec into fmtcpy.  */
 138           string = fmtcpy;
 139           *string++ = '%';
 140           while (1)
 141             {
 142               *string++ = *fmt;
 143               if ('0' <= *fmt && *fmt <= '9')
 144                 {
 145                   /* Get an idea of how much space we might need.
 146                      This might be a field width or a precision; e.g.
 147                      %1.1000f and %1000.1f both might need 1000+ bytes.
 148                      Parse the width or precision, checking for overflow.  */
 149                   int n = *fmt - '0';
 150                   while ('0' <= fmt[1] && fmt[1] <= '9')
 151                     {
 152                       if (n * 10 / 10 != n
 153                           || (n = n * 10 + (fmt[1] - '0')) < 0)
 154                         error ("Format width or precision too large");
 155                       *string++ = *++fmt;
 156                     }
 157
 158                   if (size_bound < n)
 159                     size_bound = n;
 160                 }
 161               else if (*fmt == '-' || *fmt == ' ' || *fmt == '.')
 162                 ;
 163               else
 164                 break;
 165               fmt++;
 166             }
 167           *string = 0;
 168
 169           /* Make the size bound large enough to handle floating point formats
 170              with large numbers.  */
 171           size_bound += DBL_MAX_10_EXP + 50;
 172
 173           if (size_bound < 0)
 174             error ("Format width or precision too large");
 175
 176           /* Make sure we have that much.  */
 177           if (size_bound > size_allocated)
 178             {
 179               if (big_buffer)
 180                 big_buffer = (char *) xrealloc (big_buffer, size_bound);
 181               else
 182                 big_buffer = (char *) xmalloc (size_bound);
 183               sprintf_buffer = big_buffer;
 184               size_allocated = size_bound;
 185             }
 186           minlen = 0;
 187           switch (*fmt++)
 188             {
 189             default:
 190               error ("Invalid format operation %%%c", fmt[-1]);
 191
 192 /*          case 'b': */
 193             case 'd':
 194             case 'o':
 195             case 'x':
 196               if (cnt == nargs)
 197                 error ("Not enough arguments for format string");
 198               if (sizeof (int) == sizeof (EMACS_INT))
 199                 ;
 200               else if (sizeof (long) == sizeof (EMACS_INT))
 201                 /* Insert an `l' the right place.  */
 202                 string[1] = string[0],
 203                 string[0] = string[-1],
 204                 string[-1] = 'l',
 205                 string++;
 206               else
 207                 abort ();
 208               sprintf (sprintf_buffer, fmtcpy, args[cnt++]);
 209               /* Now copy into final output, truncating as nec.  */
 210               string = sprintf_buffer;
 211               goto doit;
 212
 213             case 'f':
 214             case 'e':
 215             case 'g':
 216               {
 217                 union { double d; char *half[2]; } u;
 218                 if (cnt + 1 == nargs)
 219                   error ("not enough arguments for format string");
 220                 u.half[0] = args[cnt++];
 221                 u.half[1] = args[cnt++];
 222                 sprintf (sprintf_buffer, fmtcpy, u.d);
 223                 /* Now copy into final output, truncating as nec.  */
 224                 string = sprintf_buffer;
 225                 goto doit;
 226               }
 227
 228             case 'S':
 229               string[-1] = 's';
 230             case 's':
 231               if (cnt == nargs)
 232                 error ("not enough arguments for format string");
 233               if (fmtcpy[1] != 's')
 234                 minlen = atoi (&fmtcpy[1]);
 235               if (lispstrings)
 236                 {
 237                   string = (char *) ((struct Lisp_String *)args[cnt])->data;
 238                   tem = ((struct Lisp_String *)args[cnt])->size;
 239                   cnt++;
 240                 }
 241               else
 242                 {
 243                   string = args[cnt++];
 244                   tem = strlen (string);
 245                 }
 246               width = strwidth (string, tem);
 247               goto doit1;
 248
 249               /* Copy string into final output, truncating if no room.  */
 250             doit:
 251               /* Coming here means STRING contains ASCII only.  */
 252               width = tem = strlen (string);
 253             doit1:
 254               /* We have already calculated:
 255                  TEM -- length of STRING,
 256                  WIDTH -- columns occupied by STRING when displayed, and
 257                  MINLEN -- minimum columns of the output.  */
 258               if (minlen > 0)
 259                 {
 260                   while (minlen > width && bufsize > 0)
 261                     {
 262                       *bufptr++ = ' ';
 263                       bufsize--;
 264                       minlen--;
 265                     }
 266                   minlen = 0;
 267                 }
 268               if (tem > bufsize)
 269                 {
 270                   /* Truncate the string at character boundary.  */
 271                   tem = bufsize;
 272                   while (!CHAR_HEAD_P (string[tem - 1])) tem--;
 273                   bcopy (string, bufptr, tem);
 274                   /* We must calculate WIDTH again.  */
 275                   width = strwidth (bufptr, tem);
 276                 }
 277               else
 278                 bcopy (string, bufptr, tem);
 279               bufptr += tem;
 280               bufsize -= tem;
 281               if (minlen < 0)
 282                 {
 283                   while (minlen < - width && bufsize > 0)
 284                     {
 285                       *bufptr++ = ' ';
 286                       bufsize--;
 287                       minlen++;
 288                     }
 289                   minlen = 0;
 290                 }
 291               continue;
 292
 293             case 'c':
 294               if (cnt == nargs)
 295                 error ("not enough arguments for format string");
 296               tem = CHAR_STRING ((int) (EMACS_INT) args[cnt], charbuf, string);
 297               cnt++;
 298               string[tem] = 0;
 299               width = strwidth (string, tem);
 300               if (fmtcpy[1] != 'c')
 301                 minlen = atoi (&fmtcpy[1]);
 302               goto doit1;
 303
 304             case '%':
 305               fmt--;    /* Drop thru and this % will be treated as normal */
 306             }
 307         }
 308
 309       {
 310         /* Just some character; Copy it if the whole multi-byte form
 311            fit in the buffer.  */
 312         char *save_bufptr = bufptr;
 313
 314         do { *bufptr++ = *fmt++; }
 315         while (--bufsize > 0 && !CHAR_HEAD_P (*fmt));
 316         if (!CHAR_HEAD_P (*fmt))
 317           {
 318             bufptr = save_bufptr;
 319             break;
 320           }
 321       }
 322     };
 323
 324   /* If we had to malloc something, free it.  */
 325   if (big_buffer)
 326     xfree (big_buffer);
 327
 328   *bufptr = 0;          /* Make sure our string end with a '\0' */
 329   return bufptr - buffer;
 330 }