slang/slmisc.c

   1 /* Copyright (c) 1992, 1999, 2001, 2002 John E. Davis
   2  * This file is part of the S-Lang library.
   3  *
   4  * Trimmed down for use in GNU Midnight Commander.
   5  *
   6  * You may distribute under the terms of either the GNU General Public
   7  * License or the Perl Artistic License.
   8  */
   9 #include "slinclud.h"
  10
  11 #include "slang.h"
  12 #include "_slang.h"
  13
  14 /* p and ch may point to the same buffer */
  15 char *_SLexpand_escaped_char(char *p, char *ch)
  16 {
  17    int i = 0;
  18    int max = 0, num, base = 0;
  19    char ch1;
  20
  21    ch1 = *p++;
  22
  23    switch (ch1)
  24      {
  25       default: num = ch1; break;
  26       case 'n': num = '\n'; break;
  27       case 't': num = '\t'; break;
  28       case 'v': num = '\v'; break;
  29       case 'b': num = '\b'; break;
  30       case 'r': num = '\r'; break;
  31       case 'f': num = '\f'; break;
  32       case 'E': case 'e': num = 27; break;
  33       case 'a': num = 7;
  34         break;
  35
  36         /* octal */
  37       case '0': case '1': case '2': case '3':
  38       case '4': case '5': case '6': case '7':
  39         max = '7';
  40         base = 8; i = 2; num = ch1 - '0';
  41         break;
  42
  43       case 'd':                        /* decimal -- S-Lang extension */
  44         base = 10;
  45         i = 3;
  46         max = '9';
  47         num = 0;
  48         break;
  49
  50       case 'x':                        /* hex */
  51         base = 16;
  52         max = '9';
  53         i = 2;
  54         num = 0;
  55         break;
  56      }
  57
  58    while (i--)
  59      {
  60         ch1 = *p;
  61
  62         if ((ch1 <= max) && (ch1 >= '0'))
  63           {
  64              num = base * num + (ch1 - '0');
  65           }
  66         else if (base == 16)
  67           {
  68              ch1 |= 0x20;
  69              if ((ch1 < 'a') || ((ch1 > 'f'))) break;
  70              num = base * num + 10 + (ch1 - 'a');
  71           }
  72         else break;
  73         p++;
  74      }
  75
  76    *ch = (char) num;
  77    return p;
  78 }