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
  23 #include "lisp.h"               /* for xmalloc */
  24 #include "tparam.h"
  25 \f
  26 /* Assuming STRING is the value of a termcap string entry
  27    containing `%' constructs to expand parameters,
  28    merge in parameter values and store result in block OUTSTRING points to.
  29    LEN is the length of OUTSTRING.  If more space is needed,
  30    a block is allocated with `malloc'.
  31
  32    The value returned is the address of the resulting string.
  33    This may be OUTSTRING or may be the address of a block got with `malloc'.
  34    In the latter case, the caller must free the block.
  35
  36    The fourth and following args to tparam serve as the parameter values.  */
  37
  38 static char *tparam1 (char const *string, char *outstring, int len,
  39                       char *up, char *left, int *argp);
  40
  41 char *
  42 tparam (const char *string, char *outstring, int len,
  43         int arg0, int arg1, int arg2, int arg3)
  44 {
  45   int arg[4];
  46
  47   arg[0] = arg0;
  48   arg[1] = arg1;
  49   arg[2] = arg2;
  50   arg[3] = arg3;
  51   return tparam1 (string, outstring, len, NULL, NULL, arg);
  52 }
  53
  54 char *BC;
  55 char *UP;
  56
  57 static char tgoto_buf[50];
  58
  59 char *
  60 tgoto (const char *cm, int hpos, int vpos)
  61 {
  62   int args[2];
  63   if (!cm)
  64     return NULL;
  65   args[0] = vpos;
  66   args[1] = hpos;
  67   return tparam1 (cm, tgoto_buf, 50, UP, BC, args);
  68 }
  69
  70 static char *
  71 tparam1 (const char *string, char *outstring, int len,
  72          char *up, char *left, register int *argp)
  73 {
  74   register int c;
  75   register const char *p = string;
  76   register char *op = outstring;
  77   char *outend;
  78   char *new = 0;
  79   ptrdiff_t outlen = 0;
  80
  81   register int tem;
  82   int *old_argp = argp;                 /* can move */
  83   int *fixed_argp = argp;               /* never moves */
  84   int explicit_param_p = 0;             /* set by %p */
  85   ptrdiff_t doleft = 0;
  86   ptrdiff_t doup = 0;
  87   ptrdiff_t append_len = 0;
  88
  89   outend = outstring + len;
  90
  91   while (1)
  92     {
  93       /* If the buffer might be too short, make it bigger.  */
  94       while (outend - op - append_len <= 5)
  95         {
  96           ptrdiff_t offset = op - outstring;
  97
  98           if (outlen == 0)
  99             {
 100               outlen = len + 40;
 101               new = xmalloc (outlen);
 102               memcpy (new, outstring, offset);
 103             }
 104           else
 105             {
 106               new = xpalloc (outstring, &outlen, 1, -1, 1);
 107             }
 108
 109           op = new + offset;
 110           outend = new + outlen;
 111           outstring = new;
 112         }
 113       c = *p++;
 114       if (!c)
 115         break;
 116       if (c == '%')
 117         {
 118           c = *p++;
 119           if (explicit_param_p)
 120             explicit_param_p = 0;
 121           else
 122             tem = *argp;
 123           switch (c)
 124             {
 125             case 'd':           /* %d means output in decimal.  */
 126               if (tem < 10)
 127                 goto onedigit;
 128               if (tem < 100)
 129                 goto twodigit;
 130             case '3':           /* %3 means output in decimal, 3 digits.  */
 131               if (tem > 999)
 132                 {
 133                   *op++ = tem / 1000 + '0';
 134                   tem %= 1000;
 135                 }
 136               *op++ = tem / 100 + '0';
 137             case '2':           /* %2 means output in decimal, 2 digits.  */
 138             twodigit:
 139               tem %= 100;
 140               *op++ = tem / 10 + '0';
 141             onedigit:
 142               *op++ = tem % 10 + '0';
 143               argp++;
 144               break;
 145             case 'p':           /* %pN means use param N for next subst.  */
 146               tem = fixed_argp[(*p++) - '1'];
 147               explicit_param_p = 1;
 148               break;
 149             case 'C':
 150               /* For c-100: print quotient of value by 96, if nonzero,
 151                  then do like %+.  */
 152               if (tem >= 96)
 153                 {
 154                   *op++ = tem / 96;
 155                   tem %= 96;
 156                 }
 157             case '+':           /* %+x means add character code of char x.  */
 158               tem += *p++;
 159             case '.':           /* %. means output as character.  */
 160               if (left)
 161                 {
 162                   /* If want to forbid output of 0 and \n and \t,
 163                      and this is one of them, increment it.  */
 164                   while (tem == 0 || tem == '\n' || tem == '\t')
 165                     {
 166                       ptrdiff_t append_len_incr;
 167                       tem++;
 168                       if (argp == old_argp)
 169                         doup++, append_len_incr = strlen (up);
 170                       else
 171                         doleft++, append_len_incr = strlen (left);
 172                       if (INT_ADD_OVERFLOW (append_len, append_len_incr))
 173                         memory_full (SIZE_MAX);
 174                       append_len += append_len_incr;
 175                     }
 176                 }
 177               *op++ = tem ? tem : 0200;
 178             case 'f':           /* %f means discard next arg.  */
 179               argp++;
 180               break;
 181
 182             case 'b':           /* %b means back up one arg (and re-use it).  */
 183               argp--;
 184               break;
 185
 186             case 'r':           /* %r means interchange following two args.  */
 187               argp[0] = argp[1];
 188               argp[1] = tem;
 189               old_argp++;
 190               break;
 191
 192             case '>':           /* %>xy means if arg is > char code of x, */
 193               if (argp[0] > *p++) /* then add char code of y to the arg, */
 194                 argp[0] += *p;  /* and in any case don't output.  */
 195               p++;              /* Leave the arg to be output later.  */
 196               break;
 197
 198             case 'a':           /* %a means arithmetic.  */
 199               /* Next character says what operation.
 200                  Add or subtract either a constant or some other arg.  */
 201               /* First following character is + to add or - to subtract
 202                  or = to assign.  */
 203               /* Next following char is 'p' and an arg spec
 204                  (0100 plus position of that arg relative to this one)
 205                  or 'c' and a constant stored in a character.  */
 206               tem = p[2] & 0177;
 207               if (p[1] == 'p')
 208                 tem = argp[tem - 0100];
 209               if (p[0] == '-')
 210                 argp[0] -= tem;
 211               else if (p[0] == '+')
 212                 argp[0] += tem;
 213               else if (p[0] == '*')
 214                 argp[0] *= tem;
 215               else if (p[0] == '/')
 216                 argp[0] /= tem;
 217               else
 218                 argp[0] = tem;
 219
 220               p += 3;
 221               break;
 222
 223             case 'i':           /* %i means add one to arg, */
 224               argp[0] ++;       /* and leave it to be output later.  */
 225               argp[1] ++;       /* Increment the following arg, too!  */
 226               break;
 227
 228             case '%':           /* %% means output %; no arg.  */
 229               goto ordinary;
 230
 231             case 'n':           /* %n means xor each of next two args with 140.  */
 232               argp[0] ^= 0140;
 233               argp[1] ^= 0140;
 234               break;
 235
 236             case 'm':           /* %m means xor each of next two args with 177.  */
 237               argp[0] ^= 0177;
 238               argp[1] ^= 0177;
 239               break;
 240
 241             case 'B':           /* %B means express arg as BCD char code.  */
 242               argp[0] += 6 * (tem / 10);
 243               break;
 244
 245             case 'D':           /* %D means weird Delta Data transformation.  */
 246               argp[0] -= 2 * (tem % 16);
 247               break;
 248
 249             default:
 250               emacs_abort ();
 251             }
 252         }
 253       else
 254         /* Ordinary character in the argument string.  */
 255       ordinary:
 256         *op++ = c;
 257     }
 258   *op = 0;
 259   while (doup-- > 0)
 260     strcat (op, up);
 261   while (doleft-- > 0)
 262     strcat (op, left);
 263   return outstring;
 264 }
 265 \f
 266 #ifdef DEBUG
 267
 268 int
 269 main (int argc, char **argv)
 270 {
 271   char buf[50];
 272   int args[3];
 273   args[0] = atoi (argv[2]);
 274   args[1] = atoi (argv[3]);
 275   args[2] = atoi (argv[4]);
 276   tparam1 (argv[1], buf, 50, "LEFT", "UP", args);
 277   printf ("%s\n", buf);
 278   return 0;
 279 }
 280
 281 #endif /* DEBUG */