slang/sltoken.c

   1 /*--------------------------------*-C-*---------------------------------*
   2  * File:        sltoken.c
   3  *
   4  * Descript:    ---
   5  *
   6  * Requires:    ---
   7  *
   8  * Public:      SLexpand_escaped_char ();
   9  *              SLexpand_escaped_string ();
  10  *              SLang_extract_token ();
  11  *              SLang_guess_type ();
  12  *              SLatoi ();
  13  *
  14  * Private:     ---
  15  *
  16  * Notes:       ---
  17  *
  18  * Copyright (c) 1992, 1995 John E. Davis
  19  * All rights reserved.
  20  *
  21  * You may distribute under the terms of either the GNU General Public
  22  * License or the Perl Artistic License.
  23 \*----------------------------------------------------------------------*/
  24
  25 #include "config.h"
  26
  27 #include <stdio.h>
  28
  29
  30 #ifdef HAVE_STDLIB_H
  31 # include <stdlib.h>
  32 #endif
  33 #include <string.h>
  34 #include "_slang.h"
  35
  36 /* There are non-zeros at positions "\t %()*,/:;[]{}" */
  37
  38 static const unsigned char special_chars[256] =
  39 {
  40    /* 0 */      0,0,0,0,0,0,0,0,        0,'\t',0,0,0,0,0,0,
  41    /* 16 */     0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  42    /* 32 */     ' ',0,0,0,0,'%',0,0,    '(',')','*',0,',',0,0,'/',
  43    /* 48 */     0,0,0,0,0,0,0,0,        0,0,':',';',0,0,0,0,
  44    /* 64 */     0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  45    /* 80 */     0,0,0,0,0,0,0,0,        0,0,0,'[',0,']',0,0,
  46    /* 96 */     0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  47    /* 112 */    0,0,0,0,0,0,0,0,        0,0,0,'{',0,'}',0,0,
  48    /* 8-bit characters */
  49    /* 128 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  50    /* 144 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  51    /* 160 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  52    /* 176 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  53    /* 192 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  54    /* 208 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  55    /* 224 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0,
  56    /* 240 */    0,0,0,0,0,0,0,0,        0,0,0,0,0,0,0,0
  57 };
  58
  59 char *SLexpand_escaped_char(char *p, char *ch)
  60 {
  61    int i = 0;
  62    int max = 0, num, base = 0;
  63    char ch1;
  64
  65    ch1 = *p++;
  66
  67    switch (ch1)
  68      {
  69       default: num = ch1; break;
  70       case 'n': num = '\n'; break;
  71       case 't': num = '\t'; break;
  72       case 'v': num = '\v'; break;
  73       case 'b': num = '\b'; break;
  74       case 'r': num = '\r'; break;
  75       case 'f': num = '\f'; break;
  76       case 'E': case 'e': num = 27; break;
  77       case 'a': num = 7;
  78         break;
  79
  80         /* octal */
  81       case '0': case '1': case '2': case '3':
  82       case '4': case '5': case '6': case '7':
  83         max = '7';
  84         base = 8; i = 2; num = ch1 - '0';
  85         break;
  86
  87       case 'd':                        /* decimal -- S-Lang extension */
  88         base = 10;
  89         i = 3;
  90         max = '9';
  91         num = 0;
  92         break;
  93
  94       case 'x':                        /* hex */
  95         base = 16;
  96         max = '9';
  97         i = 2;
  98         num = 0;
  99         break;
 100      }
 101
 102    while (i--)
 103      {
 104         ch1 = *p;
 105
 106         if ((ch1 <= max) && (ch1 >= '0'))
 107           {
 108              num = base * num + (ch1 - '0');
 109           }
 110         else if (base == 16)
 111           {
 112              ch1 |= 0x20;
 113              if ((ch1 < 'a') || ((ch1 > 'f'))) break;
 114              num = base * num + 10 + (ch1 - 'a');
 115           }
 116         else break;
 117         p++;
 118      }
 119
 120    *ch = (char) num;
 121    return p;
 122 }
 123
 124 void SLexpand_escaped_string (register char *s, register char *t,
 125                               register char *tmax)
 126 {
 127    char ch;
 128
 129    while (t < tmax)
 130      {
 131         ch = *t++;
 132         if (ch == '\\')
 133           {
 134              t = SLexpand_escaped_char (t, &ch);
 135           }
 136         *s++ = ch;
 137      }
 138    *s = 0;
 139 }
 140
 141
 142 int SLang_extract_token (char **linep, char *word_parm, int byte_comp)
 143 {
 144    register char ch, *line, *word = word_parm;
 145    int string;
 146    char ch1;
 147    char *word_max;
 148
 149    word_max = word + 250;
 150
 151    line = *linep;
 152
 153    /* skip white space */
 154    while (((ch = *line) == ' ')
 155           || (ch == '\t')) line++;
 156
 157    if ((!ch) || (ch == '\n'))
 158      {
 159         *linep = line;
 160         return(0);
 161      }
 162
 163    *word++ = ch;
 164    line++;
 165
 166    /* Look for -something and rule out --something and -= something */
 167    if ((ch == '-') &&
 168        (*line != '-') && (*line != '=') && ((*line > '9') || (*line < '0')))
 169      {
 170         *word = 0;
 171         *linep = line;
 172         return 1;
 173      }
 174
 175
 176    if (ch == '"') string = 1; else string = 0;
 177    if (ch == '\'')
 178      {
 179         if ((ch = *line++) != 0)
 180           {
 181              if (ch == '\\')
 182                {
 183                   line = SLexpand_escaped_char(line, &ch1);
 184                   ch = ch1;
 185                }
 186              if (*line++ == '\'')
 187                {
 188                   --word;
 189                   sprintf(word, "%d", (int) ((unsigned char) ch));
 190                   word += strlen (word);  ch = '\'';
 191                }
 192              else SLang_Error = SYNTAX_ERROR;
 193           }
 194         else SLang_Error = SYNTAX_ERROR;
 195      }
 196    else  if (!special_chars[(unsigned char) ch])
 197      {
 198         while (ch = *line++,
 199                (ch > '"') ||
 200                ((ch != '\n') && (ch != 0) && (ch != '"')))
 201           {
 202              if (string)
 203                {
 204                   if (ch == '\\')
 205                     {
 206                        ch = *line++;
 207                        if ((ch == 0) || (ch == '\n')) break;
 208                        if (byte_comp) *word++ = '\\';
 209                        else
 210                          {
 211                             line = SLexpand_escaped_char(line - 1, &ch1);
 212                             ch = ch1;
 213                          }
 214                     }
 215                }
 216              else if (special_chars[(unsigned char) ch])
 217                {
 218                   line--;
 219                   break;
 220                }
 221
 222              *word++ = ch;
 223              if (word > word_max)
 224                {
 225                   SLang_doerror ("Token to large.");
 226                   break;
 227                }
 228           }
 229      }
 230
 231    if ((!ch) || (ch == '\n')) line--;
 232    if ((ch == '"') && string) *word++ = '"'; else if (string) SLang_Error = SYNTAX_ERROR;
 233    *word = 0;
 234    *linep = line;
 235    /* massage variable-- and ++ into --variable, etc... */
 236    if (((int) (word - word_parm) > 2)
 237        && (ch = *(word - 1), (ch == '+') || (ch == '-'))
 238        && (ch == *(word - 2)))
 239      {
 240         word--;
 241         while (word >= word_parm + 2)
 242           {
 243              *word = *(word - 2);
 244              word--;
 245           }
 246         *word-- = ch;
 247         *word-- = ch;
 248      }
 249    return(1);
 250 }
 251
 252
 253 int SLang_guess_type (char *t)
 254 {
 255    char *p;
 256    register char ch;
 257
 258    if (*t == '-') t++;
 259    p = t;
 260 #ifdef FLOAT_TYPE
 261    if (*p != '.')
 262      {
 263 #endif
 264         while ((*p >= '0') && (*p <= '9')) p++;
 265         if (t == p) return(STRING_TYPE);
 266         if ((*p == 'x') && (p == t + 1))   /* 0x?? */
 267           {
 268              p++;
 269              while (ch = *p,
 270                     ((ch >= '0') && (ch <= '9'))
 271                     || (((ch | 0x20) >= 'a') && ((ch | 0x20) <= 'f'))) p++;
 272           }
 273         if (*p == 0) return(INT_TYPE);
 274 #ifndef FLOAT_TYPE
 275         return(STRING_TYPE);
 276 #else
 277      }
 278
 279    /* now down to float case */
 280    if (*p == '.')
 281      {
 282         p++;
 283         while ((*p >= '0') && (*p <= '9')) p++;
 284      }
 285    if (*p == 0) return(FLOAT_TYPE);
 286    if ((*p != 'e') && (*p != 'E')) return(STRING_TYPE);
 287    p++;
 288    if ((*p == '-') || (*p == '+')) p++;
 289    while ((*p >= '0') && (*p <= '9')) p++;
 290    if (*p != 0) return(STRING_TYPE); else return(FLOAT_TYPE);
 291 #endif
 292 }
 293
 294 int SLatoi (unsigned char *s)
 295 {
 296    register unsigned char ch;
 297    register unsigned int value;
 298    register int base;
 299
 300    if (*s != '0') return atoi((char *) s);
 301
 302    /* look for 'x' which indicates hex */
 303    s++;
 304    if ((*s | 0x20) == 'x')
 305      {
 306         base = 16;
 307         s++;
 308         if (*s == 0)
 309           {
 310              SLang_Error = SYNTAX_ERROR;
 311              return -1;
 312           }
 313      }
 314    else base = 8;
 315
 316
 317    value = 0;
 318    while ((ch = *s++) != 0)
 319      {
 320         char ch1 = ch | 0x20;
 321         switch (ch1)
 322           {
 323            default:
 324              SLang_Error = SYNTAX_ERROR;
 325              break;
 326            case '8':
 327            case '9':
 328              if (base != 16) SLang_Error = SYNTAX_ERROR;
 329              /* drop */
 330            case '0':
 331            case '1':
 332            case '2':
 333            case '3':
 334            case '4':
 335            case '5':
 336            case '6':
 337            case '7':
 338              ch1 -= '0';
 339              break;
 340
 341            case 'a':
 342            case 'b':
 343            case 'c':
 344            case 'd':
 345            case 'e':
 346            case 'f':
 347              if (base != 16) SLang_Error = SYNTAX_ERROR;
 348              ch1 = (ch1 - 'a') + 10;
 349              break;
 350           }
 351         value = value * base + ch1;
 352      }
 353    return (int) value;
 354 }