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 #include "lisp.h"
  28
  29 extern long *xmalloc (), *xrealloc ();
  30
  31 static int doprnt1 ();
  32
  33 /* Generate output from a format-spec FORMAT,
  34    terminated at position FORMAT_END.
  35    Output goes in BUFFER, which has room for BUFSIZE chars.
  36    If the output does not fit, truncate it to fit.
  37    Returns the number of characters stored into BUFFER.
  38    ARGS points to the vector of arguments, and NARGS says how many.
  39    A double counts as two arguments.
  40    String arguments are passed as C strings.
  41    Integers are passed as C integers.  */
  42
  43 doprnt (buffer, bufsize, format, format_end, nargs, args)
  44      char *buffer;
  45      register int bufsize;
  46      char *format;
  47      char *format_end;
  48      int nargs;
  49      char **args;
  50 {
  51   return doprnt1 (0, buffer, bufsize, format, format_end, nargs, args);
  52 }
  53
  54 /* Like doprnt except that strings in ARGS are passed
  55    as Lisp_Object.  */
  56
  57 doprnt_lisp (buffer, bufsize, format, format_end, nargs, args)
  58      char *buffer;
  59      register int bufsize;
  60      char *format;
  61      char *format_end;
  62      int nargs;
  63      char **args;
  64 {
  65   return doprnt1 (1, buffer, bufsize, format, format_end, nargs, args);
  66 }
  67
  68 static int
  69 doprnt1 (lispstrings, buffer, bufsize, format, format_end, nargs, args)
  70      int lispstrings;
  71      char *buffer;
  72      register int bufsize;
  73      char *format;
  74      char *format_end;
  75      int nargs;
  76      char **args;
  77 {
  78   int cnt = 0;                  /* Number of arg to gobble next */
  79   register char *fmt = format;  /* Pointer into format string */
  80   register char *bufptr = buffer; /* Pointer into output buffer.. */
  81
  82   /* Use this for sprintf unless we need something really big.  */
  83   char tembuf[100];
  84
  85   /* Size of sprintf_buffer.  */
  86   int size_allocated = 100;
  87
  88   /* Buffer to use for sprintf.  Either tembuf or same as BIG_BUFFER.  */
  89   char *sprintf_buffer = tembuf;
  90
  91   /* Buffer we have got with malloc.  */
  92   char *big_buffer = 0;
  93
  94   register int tem;
  95   char *string;
  96   char fixed_buffer[20];        /* Default buffer for small formatting. */
  97   char *fmtcpy;
  98   int minlen;
  99   int size;                     /* Field width factor; e.g., %90d */
 100   char charbuf[2];              /* Used for %c.  */
 101
 102   if (format_end == 0)
 103     format_end = format + strlen (format);
 104
 105   if ((format_end - format + 1) < sizeof (fixed_buffer))
 106     fmtcpy = fixed_buffer;
 107   else
 108     fmtcpy = (char *) alloca (format_end - format + 1);
 109
 110   bufsize--;
 111
 112   /* Loop until end of format string or buffer full. */
 113   while (fmt != format_end && bufsize > 0)
 114     {
 115       if (*fmt == '%')  /* Check for a '%' character */
 116         {
 117           int size_bound;
 118
 119           fmt++;
 120           /* Copy this one %-spec into fmtcpy.  */
 121           string = fmtcpy;
 122           *string++ = '%';
 123           while (1)
 124             {
 125               *string++ = *fmt;
 126               if (! (*fmt >= '0' && *fmt <= '9')
 127                   && *fmt != '-' && *fmt != ' '&& *fmt != '.')
 128                 break;
 129               fmt++;
 130             }
 131           *string = 0;
 132           /* Get an idea of how much space we might need.  */
 133           size_bound = atoi (&fmtcpy[1]);
 134
 135           /* Avoid pitfall of negative "size" parameter ("%-200d"). */
 136           if (size_bound < 0)
 137             size_bound = -size_bound;
 138           size_bound += 50;
 139
 140           if (size_bound > (unsigned) (1 << (BITS_PER_INT - 1)))
 141             error ("Format padding too large");
 142
 143           /* Make sure we have that much.  */
 144           if (size_bound > size_allocated)
 145             {
 146               if (big_buffer)
 147                 big_buffer = (char *) xrealloc (big_buffer, size_bound);
 148               else
 149                 big_buffer = (char *) xmalloc (size_bound);
 150               sprintf_buffer = big_buffer;
 151               size_allocated = size_bound;
 152             }
 153           minlen = 0;
 154           switch (*fmt++)
 155             {
 156             default:
 157               error ("Invalid format operation %%%c", fmt[-1]);
 158
 159 /*          case 'b': */
 160             case 'd':
 161             case 'o':
 162             case 'x':
 163               if (cnt == nargs)
 164                 error ("Not enough arguments for format string");
 165               if (sizeof (int) == sizeof (EMACS_INT))
 166                 ;
 167               else if (sizeof (long) == sizeof (EMACS_INT))
 168                 /* Insert an `l' the right place.  */
 169                 string[1] = string[0],
 170                 string[0] = string[-1],
 171                 string[-1] = 'l',
 172                 string++;
 173               else
 174                 abort ();
 175               sprintf (sprintf_buffer, fmtcpy, args[cnt++]);
 176               /* Now copy into final output, truncating as nec.  */
 177               string = sprintf_buffer;
 178               goto doit;
 179
 180             case 'f':
 181             case 'e':
 182             case 'g':
 183               {
 184                 union { double d; char *half[2]; } u;
 185                 if (cnt + 1 == nargs)
 186                   error ("not enough arguments for format string");
 187                 u.half[0] = args[cnt++];
 188                 u.half[1] = args[cnt++];
 189                 sprintf (sprintf_buffer, fmtcpy, u.d);
 190                 /* Now copy into final output, truncating as nec.  */
 191                 string = sprintf_buffer;
 192                 goto doit;
 193               }
 194
 195             case 'S':
 196               string[-1] = 's';
 197             case 's':
 198               if (cnt == nargs)
 199                 error ("not enough arguments for format string");
 200               if (fmtcpy[1] != 's')
 201                 minlen = atoi (&fmtcpy[1]);
 202               if (lispstrings)
 203                 {
 204                   string = (char *) XSTRING (((Lisp_Object *) args)[cnt])->data;
 205                   tem = XSTRING (((Lisp_Object *) args)[cnt])->size;
 206                   cnt++;
 207                 }
 208               else
 209                 {
 210                   string = args[cnt++];
 211                   tem = strlen (string);
 212                 }
 213               goto doit1;
 214
 215               /* Copy string into final output, truncating if no room.  */
 216             doit:
 217               tem = strlen (string);
 218             doit1:
 219               if (minlen > 0)
 220                 {
 221                   while (minlen > tem && bufsize > 0)
 222                     {
 223                       *bufptr++ = ' ';
 224                       bufsize--;
 225                       minlen--;
 226                     }
 227                   minlen = 0;
 228                 }
 229               if (tem > bufsize)
 230                 tem = bufsize;
 231               bcopy (string, bufptr, tem);
 232               bufptr += tem;
 233               bufsize -= tem;
 234               if (minlen < 0)
 235                 {
 236                   while (minlen < - tem && bufsize > 0)
 237                     {
 238                       *bufptr++ = ' ';
 239                       bufsize--;
 240                       minlen++;
 241                     }
 242                   minlen = 0;
 243                 }
 244               continue;
 245
 246             case 'c':
 247               if (cnt == nargs)
 248                 error ("not enough arguments for format string");
 249               *charbuf = (EMACS_INT) args[cnt++];
 250               string = charbuf;
 251               tem = 1;
 252               if (fmtcpy[1] != 'c')
 253                 minlen = atoi (&fmtcpy[1]);
 254               goto doit1;
 255
 256             case '%':
 257               fmt--;    /* Drop thru and this % will be treated as normal */
 258             }
 259         }
 260       *bufptr++ = *fmt++;       /* Just some characters; Copy 'em */
 261       bufsize--;
 262     };
 263
 264   /* If we had to malloc something, free it.  */
 265   if (big_buffer)
 266     xfree (big_buffer);
 267
 268   *bufptr = 0;          /* Make sure our string end with a '\0' */
 269   return bufptr - buffer;
 270 }