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, 2010  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 #include <setjmp.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 "character.h"
  50
  51 /* Generate output from a format-spec FORMAT,
  52    terminated at position FORMAT_END.
  53    Output goes in BUFFER, which has room for BUFSIZE chars.
  54    If the output does not fit, truncate it to fit.
  55    Returns the number of bytes stored into BUFFER.
  56    ARGS points to the vector of arguments, and NARGS says how many.
  57    A double counts as two arguments.
  58    String arguments are passed as C strings.
  59    Integers are passed as C integers.  */
  60
  61 int
  62 doprnt (char *buffer, register int bufsize, char *format, char *format_end, int nargs, char **args)
  63 {
  64   int cnt = 0;                  /* Number of arg to gobble next */
  65   register char *fmt = format;  /* Pointer into format string */
  66   register char *bufptr = buffer; /* Pointer into output buffer.. */
  67
  68   /* Use this for sprintf unless we need something really big.  */
  69   char tembuf[DBL_MAX_10_EXP + 100];
  70
  71   /* Size of sprintf_buffer.  */
  72   unsigned size_allocated = sizeof (tembuf);
  73
  74   /* Buffer to use for sprintf.  Either tembuf or same as BIG_BUFFER.  */
  75   char *sprintf_buffer = tembuf;
  76
  77   /* Buffer we have got with malloc.  */
  78   char *big_buffer = 0;
  79
  80   register int tem;
  81   unsigned char *string;
  82   char fixed_buffer[20];        /* Default buffer for small formatting. */
  83   char *fmtcpy;
  84   int minlen;
  85   unsigned char charbuf[MAX_MULTIBYTE_LENGTH + 1];      /* Used for %c.  */
  86
  87   if (format_end == 0)
  88     format_end = format + strlen (format);
  89
  90   if ((format_end - format + 1) < sizeof (fixed_buffer))
  91     fmtcpy = fixed_buffer;
  92   else
  93     fmtcpy = (char *) alloca (format_end - format + 1);
  94
  95   bufsize--;
  96
  97   /* Loop until end of format string or buffer full. */
  98   while (fmt != format_end && bufsize > 0)
  99     {
 100       if (*fmt == '%')  /* Check for a '%' character */
 101         {
 102           unsigned size_bound = 0;
 103           int width;            /* Columns occupied by STRING.  */
 104
 105           fmt++;
 106           /* Copy this one %-spec into fmtcpy.  */
 107           string = (unsigned char *) fmtcpy;
 108           *string++ = '%';
 109           while (1)
 110             {
 111               *string++ = *fmt;
 112               if ('0' <= *fmt && *fmt <= '9')
 113                 {
 114                   /* Get an idea of how much space we might need.
 115                      This might be a field width or a precision; e.g.
 116                      %1.1000f and %1000.1f both might need 1000+ bytes.
 117                      Parse the width or precision, checking for overflow.  */
 118                   unsigned n = *fmt - '0';
 119                   while ('0' <= fmt[1] && fmt[1] <= '9')
 120                     {
 121                       if (n * 10 + fmt[1] - '0' < n)
 122                         error ("Format width or precision too large");
 123                       n = n * 10 + fmt[1] - '0';
 124                       *string++ = *++fmt;
 125                     }
 126
 127                   if (size_bound < n)
 128                     size_bound = n;
 129                 }
 130               else if (*fmt == '-' || *fmt == ' ' || *fmt == '.' || *fmt == '+')
 131                 ;
 132               else
 133                 break;
 134               fmt++;
 135             }
 136           *string = 0;
 137
 138           /* Make the size bound large enough to handle floating point formats
 139              with large numbers.  */
 140           if (size_bound + DBL_MAX_10_EXP + 50 < size_bound)
 141             error ("Format width or precision too large");
 142           size_bound += DBL_MAX_10_EXP + 50;
 143
 144           /* Make sure we have that much.  */
 145           if (size_bound > size_allocated)
 146             {
 147               if (big_buffer)
 148                 big_buffer = (char *) xrealloc (big_buffer, size_bound);
 149               else
 150                 big_buffer = (char *) xmalloc (size_bound);
 151               sprintf_buffer = big_buffer;
 152               size_allocated = size_bound;
 153             }
 154           minlen = 0;
 155           switch (*fmt++)
 156             {
 157             default:
 158               error ("Invalid format operation %%%c", fmt[-1]);
 159
 160 /*          case 'b': */
 161             case 'd':
 162             case 'o':
 163             case 'x':
 164               if (cnt == nargs)
 165                 error ("Not enough arguments for format string");
 166               if (sizeof (int) == sizeof (EMACS_INT))
 167                 ;
 168               else if (sizeof (long) == sizeof (EMACS_INT))
 169                 /* Insert an `l' the right place.  */
 170                 string[1] = string[0],
 171                 string[0] = string[-1],
 172                 string[-1] = 'l',
 173                 string++;
 174               else
 175                 abort ();
 176               sprintf (sprintf_buffer, fmtcpy, args[cnt++]);
 177               /* Now copy into final output, truncating as nec.  */
 178               string = (unsigned char *) sprintf_buffer;
 179               goto doit;
 180
 181             case 'f':
 182             case 'e':
 183             case 'g':
 184               {
 185                 union { double d; char *half[2]; } u;
 186                 if (cnt + 1 == nargs)
 187                   error ("Not enough arguments for format string");
 188                 u.half[0] = args[cnt++];
 189                 u.half[1] = args[cnt++];
 190                 sprintf (sprintf_buffer, fmtcpy, u.d);
 191                 /* Now copy into final output, truncating as nec.  */
 192                 string = (unsigned char *) sprintf_buffer;
 193                 goto doit;
 194               }
 195
 196             case 'S':
 197               string[-1] = 's';
 198             case 's':
 199               if (cnt == nargs)
 200                 error ("Not enough arguments for format string");
 201               if (fmtcpy[1] != 's')
 202                 minlen = atoi (&fmtcpy[1]);
 203               string = (unsigned char *) args[cnt++];
 204               tem = strlen (string);
 205               width = strwidth (string, tem);
 206               goto doit1;
 207
 208               /* Copy string into final output, truncating if no room.  */
 209             doit:
 210               /* Coming here means STRING contains ASCII only.  */
 211               width = tem = strlen (string);
 212             doit1:
 213               /* We have already calculated:
 214                  TEM -- length of STRING,
 215                  WIDTH -- columns occupied by STRING when displayed, and
 216                  MINLEN -- minimum columns of the output.  */
 217               if (minlen > 0)
 218                 {
 219                   while (minlen > width && bufsize > 0)
 220                     {
 221                       *bufptr++ = ' ';
 222                       bufsize--;
 223                       minlen--;
 224                     }
 225                   minlen = 0;
 226                 }
 227               if (tem > bufsize)
 228                 {
 229                   /* Truncate the string at character boundary.  */
 230                   tem = bufsize;
 231                   while (!CHAR_HEAD_P (string[tem - 1])) tem--;
 232                   bcopy (string, bufptr, tem);
 233                   /* We must calculate WIDTH again.  */
 234                   width = strwidth (bufptr, tem);
 235                 }
 236               else
 237                 bcopy (string, bufptr, tem);
 238               bufptr += tem;
 239               bufsize -= tem;
 240               if (minlen < 0)
 241                 {
 242                   while (minlen < - width && bufsize > 0)
 243                     {
 244                       *bufptr++ = ' ';
 245                       bufsize--;
 246                       minlen++;
 247                     }
 248                   minlen = 0;
 249                 }
 250               continue;
 251
 252             case 'c':
 253               if (cnt == nargs)
 254                 error ("Not enough arguments for format string");
 255               tem = CHAR_STRING ((int) (EMACS_INT) args[cnt], charbuf);
 256               string = charbuf;
 257               cnt++;
 258               string[tem] = 0;
 259               width = strwidth (string, tem);
 260               if (fmtcpy[1] != 'c')
 261                 minlen = atoi (&fmtcpy[1]);
 262               goto doit1;
 263
 264             case '%':
 265               fmt--;    /* Drop thru and this % will be treated as normal */
 266             }
 267         }
 268
 269       {
 270         /* Just some character; Copy it if the whole multi-byte form
 271            fit in the buffer.  */
 272         char *save_bufptr = bufptr;
 273
 274         do { *bufptr++ = *fmt++; }
 275         while (--bufsize > 0 && !CHAR_HEAD_P (*fmt));
 276         if (!CHAR_HEAD_P (*fmt))
 277           {
 278             bufptr = save_bufptr;
 279             break;
 280           }
 281       }
 282     };
 283
 284   /* If we had to malloc something, free it.  */
 285   xfree (big_buffer);
 286
 287   *bufptr = 0;          /* Make sure our string end with a '\0' */
 288   return bufptr - buffer;
 289 }
 290
 291 /* arch-tag: aa0ab528-7c5f-4c73-894c-aa2526a1efb3
 292    (do not change this comment) */