src/tparam.c

   1 /* Merge parameters into a termcap entry string.
   2    Copyright (C) 1985, 1987, 1993, 1995, 2000, 2001, 2002, 2003, 2004,
   3                  2005, 2006, 2007, 2008  Free Software Foundation, Inc.
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; see the file COPYING.  If not, write to
  17 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  18 Boston, MA 02110-1301, USA.  */
  19
  20 /* Emacs config.h may rename various library functions such as malloc.  */
  21 #include <config.h>
  22 #include <setjmp.h>
  23 #include "lisp.h"               /* for xmalloc */
  24 #include "tparam.h"
  25
  26 #ifndef NULL
  27 #define NULL (char *) 0
  28 #endif
  29 \f
  30 /* Assuming STRING is the value of a termcap string entry
  31    containing `%' constructs to expand parameters,
  32    merge in parameter values and store result in block OUTSTRING points to.
  33    LEN is the length of OUTSTRING.  If more space is needed,
  34    a block is allocated with `malloc'.
  35
  36    The value returned is the address of the resulting string.
  37    This may be OUTSTRING or may be the address of a block got with `malloc'.
  38    In the latter case, the caller must free the block.
  39
  40    The fourth and following args to tparam serve as the parameter values.  */
  41
  42 static char *tparam1 (char const *string, char *outstring, int len,
  43                       char *up, char *left, int *argp);
  44
  45 char *
  46 tparam (const char *string, char *outstring, int len,
  47         int arg0, int arg1, int arg2, int arg3)
  48 {
  49   int arg[4];
  50
  51   arg[0] = arg0;
  52   arg[1] = arg1;
  53   arg[2] = arg2;
  54   arg[3] = arg3;
  55   return tparam1 (string, outstring, len, NULL, NULL, arg);
  56 }
  57
  58 char *BC;
  59 char *UP;
  60
  61 static char tgoto_buf[50];
  62
  63 char *
  64 tgoto (const char *cm, int hpos, int vpos)
  65 {
  66   int args[2];
  67   if (!cm)
  68     return NULL;
  69   args[0] = vpos;
  70   args[1] = hpos;
  71   return tparam1 (cm, tgoto_buf, 50, UP, BC, args);
  72 }
  73
  74 static char *
  75 tparam1 (const char *string, char *outstring, int len,
  76          char *up, char *left, register int *argp)
  77 {
  78   register int c;
  79   register const char *p = string;
  80   register char *op = outstring;
  81   char *outend;
  82   char *new = 0;
  83   ptrdiff_t outlen = 0;
  84
  85   register int tem;
  86   int *old_argp = argp;                 /* can move */
  87   int *fixed_argp = argp;               /* never moves */
  88   int explicit_param_p = 0;             /* set by %p */
  89   ptrdiff_t doleft = 0;
  90   ptrdiff_t doup = 0;
  91   ptrdiff_t append_len = 0;
  92
  93   outend = outstring + len;
  94
  95   while (1)
  96     {
  97       /* If the buffer might be too short, make it bigger.  */
  98       while (outend - op - append_len <= 5)
  99         {
 100           ptrdiff_t offset = op - outstring;
 101
 102           if (outlen == 0)
 103             {
 104               outlen = len + 40;
 105               new = (char *) xmalloc (outlen);
 106               memcpy (new, outstring, offset);
 107             }
 108           else
 109             {
 110               new = xpalloc (outstring, &outlen, 1, -1, 1);
 111             }
 112
 113           op = new + offset;
 114           outend = new + outlen;
 115           outstring = new;
 116         }
 117       c = *p++;
 118       if (!c)
 119         break;
 120       if (c == '%')
 121         {
 122           c = *p++;
 123           if (explicit_param_p)
 124             explicit_param_p = 0;
 125           else
 126             tem = *argp;
 127           switch (c)
 128             {
 129             case 'd':           /* %d means output in decimal.  */
 130               if (tem < 10)
 131                 goto onedigit;
 132               if (tem < 100)
 133                 goto twodigit;
 134             case '3':           /* %3 means output in decimal, 3 digits.  */
 135               if (tem > 999)
 136                 {
 137                   *op++ = tem / 1000 + '0';
 138                   tem %= 1000;
 139                 }
 140               *op++ = tem / 100 + '0';
 141             case '2':           /* %2 means output in decimal, 2 digits.  */
 142             twodigit:
 143               tem %= 100;
 144               *op++ = tem / 10 + '0';
 145             onedigit:
 146               *op++ = tem % 10 + '0';
 147               argp++;
 148               break;
 149             case 'p':           /* %pN means use param N for next subst.  */
 150               tem = fixed_argp[(*p++) - '1'];
 151               explicit_param_p = 1;
 152               break;
 153             case 'C':
 154               /* For c-100: print quotient of value by 96, if nonzero,
 155                  then do like %+.  */
 156               if (tem >= 96)
 157                 {
 158                   *op++ = tem / 96;
 159                   tem %= 96;
 160                 }
 161             case '+':           /* %+x means add character code of char x.  */
 162               tem += *p++;
 163             case '.':           /* %. means output as character.  */
 164               if (left)
 165                 {
 166                   /* If want to forbid output of 0 and \n and \t,
 167                      and this is one of them, increment it.  */
 168                   while (tem == 0 || tem == '\n' || tem == '\t')
 169                     {
 170                       ptrdiff_t append_len_incr;
 171                       tem++;
 172                       if (argp == old_argp)
 173                         doup++, append_len_incr = strlen (up);
 174                       else
 175                         doleft++, append_len_incr = strlen (left);
 176                       if (INT_ADD_OVERFLOW (append_len, append_len_incr))
 177                         memory_full (SIZE_MAX);
 178                       append_len += append_len_incr;
 179                     }
 180                 }
 181               *op++ = tem ? tem : 0200;
 182             case 'f':           /* %f means discard next arg.  */
 183               argp++;
 184               break;
 185
 186             case 'b':           /* %b means back up one arg (and re-use it).  */
 187               argp--;
 188               break;
 189
 190             case 'r':           /* %r means interchange following two args.  */
 191               argp[0] = argp[1];
 192               argp[1] = tem;
 193               old_argp++;
 194               break;
 195
 196             case '>':           /* %>xy means if arg is > char code of x, */
 197               if (argp[0] > *p++) /* then add char code of y to the arg, */
 198                 argp[0] += *p;  /* and in any case don't output.  */
 199               p++;              /* Leave the arg to be output later.  */
 200               break;
 201
 202             case 'a':           /* %a means arithmetic.  */
 203               /* Next character says what operation.
 204                  Add or subtract either a constant or some other arg.  */
 205               /* First following character is + to add or - to subtract
 206                  or = to assign.  */
 207               /* Next following char is 'p' and an arg spec
 208                  (0100 plus position of that arg relative to this one)
 209                  or 'c' and a constant stored in a character.  */
 210               tem = p[2] & 0177;
 211               if (p[1] == 'p')
 212                 tem = argp[tem - 0100];
 213               if (p[0] == '-')
 214                 argp[0] -= tem;
 215               else if (p[0] == '+')
 216                 argp[0] += tem;
 217               else if (p[0] == '*')
 218                 argp[0] *= tem;
 219               else if (p[0] == '/')
 220                 argp[0] /= tem;
 221               else
 222                 argp[0] = tem;
 223
 224               p += 3;
 225               break;
 226
 227             case 'i':           /* %i means add one to arg, */
 228               argp[0] ++;       /* and leave it to be output later.  */
 229               argp[1] ++;       /* Increment the following arg, too!  */
 230               break;
 231
 232             case '%':           /* %% means output %; no arg.  */
 233               goto ordinary;
 234
 235             case 'n':           /* %n means xor each of next two args with 140.  */
 236               argp[0] ^= 0140;
 237               argp[1] ^= 0140;
 238               break;
 239
 240             case 'm':           /* %m means xor each of next two args with 177.  */
 241               argp[0] ^= 0177;
 242               argp[1] ^= 0177;
 243               break;
 244
 245             case 'B':           /* %B means express arg as BCD char code.  */
 246               argp[0] += 6 * (tem / 10);
 247               break;
 248
 249             case 'D':           /* %D means weird Delta Data transformation.  */
 250               argp[0] -= 2 * (tem % 16);
 251               break;
 252
 253             default:
 254               abort ();
 255             }
 256         }
 257       else
 258         /* Ordinary character in the argument string.  */
 259       ordinary:
 260         *op++ = c;
 261     }
 262   *op = 0;
 263   while (doup-- > 0)
 264     strcat (op, up);
 265   while (doleft-- > 0)
 266     strcat (op, left);
 267   return outstring;
 268 }
 269 \f
 270 #ifdef DEBUG
 271
 272 int
 273 main (int argc, char **argv)
 274 {
 275   char buf[50];
 276   int args[3];
 277   args[0] = atoi (argv[2]);
 278   args[1] = atoi (argv[3]);
 279   args[2] = atoi (argv[4]);
 280   tparam1 (argv[1], buf, 50, "LEFT", "UP", args);
 281   printf ("%s\n", buf);
 282   return 0;
 283 }
 284
 285 #endif /* DEBUG */