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, 2001, 2002, 2003, 2004, 2005,
   5                  2006, 2007, 2008, 2009  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   int cnt = 0;                  /* Number of arg to gobble next */
  72   register char *fmt = format;  /* Pointer into format string */
  73   register char *bufptr = buffer; /* Pointer into output buffer.. */
  74
  75   /* Use this for sprintf unless we need something really big.  */
  76   char tembuf[DBL_MAX_10_EXP + 100];
  77
  78   /* Size of sprintf_buffer.  */
  79   unsigned size_allocated = sizeof (tembuf);
  80
  81   /* Buffer to use for sprintf.  Either tembuf or same as BIG_BUFFER.  */
  82   char *sprintf_buffer = tembuf;
  83
  84   /* Buffer we have got with malloc.  */
  85   char *big_buffer = 0;
  86
  87   register int tem;
  88   unsigned char *string;
  89   char fixed_buffer[20];        /* Default buffer for small formatting. */
  90   char *fmtcpy;
  91   int minlen;
  92   unsigned char charbuf[MAX_MULTIBYTE_LENGTH + 1];      /* Used for %c.  */
  93
  94   if (format_end == 0)
  95     format_end = format + strlen (format);
  96
  97   if ((format_end - format + 1) < sizeof (fixed_buffer))
  98     fmtcpy = fixed_buffer;
  99   else
 100     fmtcpy = (char *) alloca (format_end - format + 1);
 101
 102   bufsize--;
 103
 104   /* Loop until end of format string or buffer full. */
 105   while (fmt != format_end && bufsize > 0)
 106     {
 107       if (*fmt == '%')  /* Check for a '%' character */
 108         {
 109           unsigned size_bound = 0;
 110           int width;            /* Columns occupied by STRING.  */
 111
 112           fmt++;
 113           /* Copy this one %-spec into fmtcpy.  */
 114           string = (unsigned char *) fmtcpy;
 115           *string++ = '%';
 116           while (1)
 117             {
 118               *string++ = *fmt;
 119               if ('0' <= *fmt && *fmt <= '9')
 120                 {
 121                   /* Get an idea of how much space we might need.
 122                      This might be a field width or a precision; e.g.
 123                      %1.1000f and %1000.1f both might need 1000+ bytes.
 124                      Parse the width or precision, checking for overflow.  */
 125                   unsigned n = *fmt - '0';
 126                   while ('0' <= fmt[1] && fmt[1] <= '9')
 127                     {
 128                       if (n * 10 / 10 != n
 129                           || (n = n * 10 + (fmt[1] - '0')) < n)
 130                         error ("Format width or precision too large");
 131                       *string++ = *++fmt;
 132                     }
 133
 134                   if (size_bound < n)
 135                     size_bound = n;
 136                 }
 137               else if (*fmt == '-' || *fmt == ' ' || *fmt == '.' || *fmt == '+')
 138                 ;
 139               else
 140                 break;
 141               fmt++;
 142             }
 143           *string = 0;
 144
 145           /* Make the size bound large enough to handle floating point formats
 146              with large numbers.  */
 147           if (size_bound + DBL_MAX_10_EXP + 50 < size_bound)
 148             error ("Format width or precision too large");
 149           size_bound += DBL_MAX_10_EXP + 50;
 150
 151           /* Make sure we have that much.  */
 152           if (size_bound > size_allocated)
 153             {
 154               if (big_buffer)
 155                 big_buffer = (char *) xrealloc (big_buffer, size_bound);
 156               else
 157                 big_buffer = (char *) xmalloc (size_bound);
 158               sprintf_buffer = big_buffer;
 159               size_allocated = size_bound;
 160             }
 161           minlen = 0;
 162           switch (*fmt++)
 163             {
 164             default:
 165               error ("Invalid format operation %%%c", fmt[-1]);
 166
 167 /*          case 'b': */
 168             case 'd':
 169             case 'o':
 170             case 'x':
 171               if (cnt == nargs)
 172                 error ("Not enough arguments for format string");
 173               if (sizeof (int) == sizeof (EMACS_INT))
 174                 ;
 175               else if (sizeof (long) == sizeof (EMACS_INT))
 176                 /* Insert an `l' the right place.  */
 177                 string[1] = string[0],
 178                 string[0] = string[-1],
 179                 string[-1] = 'l',
 180                 string++;
 181               else
 182                 abort ();
 183               sprintf (sprintf_buffer, fmtcpy, args[cnt++]);
 184               /* Now copy into final output, truncating as nec.  */
 185               string = (unsigned char *) sprintf_buffer;
 186               goto doit;
 187
 188             case 'f':
 189             case 'e':
 190             case 'g':
 191               {
 192                 union { double d; char *half[2]; } u;
 193                 if (cnt + 1 == nargs)
 194                   error ("Not enough arguments for format string");
 195                 u.half[0] = args[cnt++];
 196                 u.half[1] = args[cnt++];
 197                 sprintf (sprintf_buffer, fmtcpy, u.d);
 198                 /* Now copy into final output, truncating as nec.  */
 199                 string = (unsigned char *) sprintf_buffer;
 200                 goto doit;
 201               }
 202
 203             case 'S':
 204               string[-1] = 's';
 205             case 's':
 206               if (cnt == nargs)
 207                 error ("Not enough arguments for format string");
 208               if (fmtcpy[1] != 's')
 209                 minlen = atoi (&fmtcpy[1]);
 210               string = (unsigned char *) args[cnt++];
 211               tem = strlen (string);
 212               width = strwidth (string, tem);
 213               goto doit1;
 214
 215               /* Copy string into final output, truncating if no room.  */
 216             doit:
 217               /* Coming here means STRING contains ASCII only.  */
 218               width = tem = strlen (string);
 219             doit1:
 220               /* We have already calculated:
 221                  TEM -- length of STRING,
 222                  WIDTH -- columns occupied by STRING when displayed, and
 223                  MINLEN -- minimum columns of the output.  */
 224               if (minlen > 0)
 225                 {
 226                   while (minlen > width && bufsize > 0)
 227                     {
 228                       *bufptr++ = ' ';
 229                       bufsize--;
 230                       minlen--;
 231                     }
 232                   minlen = 0;
 233                 }
 234               if (tem > bufsize)
 235                 {
 236                   /* Truncate the string at character boundary.  */
 237                   tem = bufsize;
 238                   while (!CHAR_HEAD_P (string[tem - 1])) tem--;
 239                   bcopy (string, bufptr, tem);
 240                   /* We must calculate WIDTH again.  */
 241                   width = strwidth (bufptr, tem);
 242                 }
 243               else
 244                 bcopy (string, bufptr, tem);
 245               bufptr += tem;
 246               bufsize -= tem;
 247               if (minlen < 0)
 248                 {
 249                   while (minlen < - width && bufsize > 0)
 250                     {
 251                       *bufptr++ = ' ';
 252                       bufsize--;
 253                       minlen++;
 254                     }
 255                   minlen = 0;
 256                 }
 257               continue;
 258
 259             case 'c':
 260               if (cnt == nargs)
 261                 error ("Not enough arguments for format string");
 262               tem = CHAR_STRING ((int) (EMACS_INT) args[cnt], charbuf);
 263               string = charbuf;
 264               cnt++;
 265               string[tem] = 0;
 266               width = strwidth (string, tem);
 267               if (fmtcpy[1] != 'c')
 268                 minlen = atoi (&fmtcpy[1]);
 269               goto doit1;
 270
 271             case '%':
 272               fmt--;    /* Drop thru and this % will be treated as normal */
 273             }
 274         }
 275
 276       {
 277         /* Just some character; Copy it if the whole multi-byte form
 278            fit in the buffer.  */
 279         char *save_bufptr = bufptr;
 280
 281         do { *bufptr++ = *fmt++; }
 282         while (--bufsize > 0 && !CHAR_HEAD_P (*fmt));
 283         if (!CHAR_HEAD_P (*fmt))
 284           {
 285             bufptr = save_bufptr;
 286             break;
 287           }
 288       }
 289     };
 290
 291   /* If we had to malloc something, free it.  */
 292   xfree (big_buffer);
 293
 294   *bufptr = 0;          /* Make sure our string end with a '\0' */
 295   return bufptr - buffer;
 296 }
 297
 298 /* arch-tag: aa0ab528-7c5f-4c73-894c-aa2526a1efb3
 299    (do not change this comment) */