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