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 #ifdef HAVE_UNISTD_H
  33 #include <unistd.h>
  34 #endif
  35
  36 #ifdef HAVE_STDLIB_H
  37 #include <stdlib.h>
  38 #endif
  39
  40 #include "lisp.h"
  41
  42 #ifndef DBL_MAX_10_EXP
  43 #define DBL_MAX_10_EXP 308 /* IEEE double */
  44 #endif
  45
  46 /* Since we use the macro CHAR_HEAD_P, we have to include this, but
  47    don't have to include others because CHAR_HEAD_P does not contains
  48    another macro.  */
  49 #include "charset.h"
  50
  51 static int doprnt1 ();
  52
  53 /* Generate output from a format-spec FORMAT,
  54    terminated at position FORMAT_END.
  55    Output goes in BUFFER, which has room for BUFSIZE chars.
  56    If the output does not fit, truncate it to fit.
  57    Returns the number of characters stored into BUFFER.
  58    ARGS points to the vector of arguments, and NARGS says how many.
  59    A double counts as two arguments.
  60    String arguments are passed as C strings.
  61    Integers are passed as C integers.  */
  62
  63 int
  64 doprnt (buffer, bufsize, format, format_end, nargs, args)
  65      char *buffer;
  66      register int bufsize;
  67      char *format;
  68      char *format_end;
  69      int nargs;
  70      char **args;
  71 {
  72   return doprnt1 (0, buffer, bufsize, format, format_end, nargs, args);
  73 }
  74
  75 /* Like doprnt except that strings in ARGS are passed
  76    as Lisp_Object.  */
  77
  78 int
  79 doprnt_lisp (buffer, bufsize, format, format_end, nargs, args)
  80      char *buffer;
  81      register int bufsize;
  82      char *format;
  83      char *format_end;
  84      int nargs;
  85      char **args;
  86 {
  87   return doprnt1 (1, buffer, bufsize, format, format_end, nargs, args);
  88 }
  89
  90 static int
  91 doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
  92      int lispstrings;
  93      char *buffer;
  94      register int bufsize;
  95      char *format;
  96      char *format_end;
  97      int nargs;
  98      char **args;
  99 {
 100   int cnt = 0;                  /* Number of arg to gobble next */
 101   register char *fmt = format;  /* Pointer into format string */
 102   register char *bufptr = buffer; /* Pointer into output buffer.. */
 103
 104   /* Use this for sprintf unless we need something really big.  */
 105   char tembuf[DBL_MAX_10_EXP + 100];
 106
 107   /* Size of sprintf_buffer.  */
 108   int size_allocated = sizeof (tembuf);
 109
 110   /* Buffer to use for sprintf.  Either tembuf or same as BIG_BUFFER.  */
 111   char *sprintf_buffer = tembuf;
 112
 113   /* Buffer we have got with malloc.  */
 114   char *big_buffer = 0;
 115
 116   register int tem;
 117   unsigned char *string;
 118   char fixed_buffer[20];        /* Default buffer for small formatting. */
 119   char *fmtcpy;
 120   int minlen;
 121   unsigned char charbuf[5];     /* Used for %c.  */
 122
 123   if (format_end == 0)
 124     format_end = format + strlen (format);
 125
 126   if ((format_end - format + 1) < sizeof (fixed_buffer))
 127     fmtcpy = fixed_buffer;
 128   else
 129     fmtcpy = (char *) alloca (format_end - format + 1);
 130
 131   bufsize--;
 132
 133   /* Loop until end of format string or buffer full. */
 134   while (fmt != format_end && bufsize > 0)
 135     {
 136       if (*fmt == '%')  /* Check for a '%' character */
 137         {
 138           int size_bound = 0;
 139           int width;            /* Columns occupied by STRING.  */
 140
 141           fmt++;
 142           /* Copy this one %-spec into fmtcpy.  */
 143           string = (unsigned char *)fmtcpy;
 144           *string++ = '%';
 145           while (1)
 146             {
 147               *string++ = *fmt;
 148               if ('0' <= *fmt && *fmt <= '9')
 149                 {
 150                   /* Get an idea of how much space we might need.
 151                      This might be a field width or a precision; e.g.
 152                      %1.1000f and %1000.1f both might need 1000+ bytes.
 153                      Parse the width or precision, checking for overflow.  */
 154                   int n = *fmt - '0';
 155                   while ('0' <= fmt[1] && fmt[1] <= '9')
 156                     {
 157                       if (n * 10 / 10 != n
 158                           || (n = n * 10 + (fmt[1] - '0')) < 0)
 159                         error ("Format width or precision too large");
 160                       *string++ = *++fmt;
 161                     }
 162
 163                   if (size_bound < n)
 164                     size_bound = n;
 165                 }
 166               else if (*fmt == '-' || *fmt == ' ' || *fmt == '.')
 167                 ;
 168               else
 169                 break;
 170               fmt++;
 171             }
 172           *string = 0;
 173
 174           /* Make the size bound large enough to handle floating point formats
 175              with large numbers.  */
 176           size_bound += DBL_MAX_10_EXP + 50;
 177
 178           if (size_bound < 0)
 179             error ("Format width or precision too large");
 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 }