slang/slmisc.c

   1 /* Copyright (c) 1992, 1999, 2001, 2002, 2003 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 #define _GNU_SOURCE
  10 #include "slinclud.h"
  11
  12 #include "slang.h"
  13 #include "_slang.h"
  14 const int SLang_Version = SLANG_VERSION;
  15
  16 /* p and ch may point to the same buffer */
  17 char *_SLexpand_escaped_char(char *p, char *ch)
  18 {
  19    int i = 0;
  20    int max = 0, num, base = 0;
  21    char ch1;
  22
  23    ch1 = *p++;
  24
  25    switch (ch1)
  26      {
  27       default: num = ch1; break;
  28       case 'n': num = '\n'; break;
  29       case 't': num = '\t'; break;
  30       case 'v': num = '\v'; break;
  31       case 'b': num = '\b'; break;
  32       case 'r': num = '\r'; break;
  33       case 'f': num = '\f'; break;
  34       case 'E': case 'e': num = 27; break;
  35       case 'a': num = 7;
  36         break;
  37
  38         /* octal */
  39       case '0': case '1': case '2': case '3':
  40       case '4': case '5': case '6': case '7':
  41         max = '7';
  42         base = 8; i = 2; num = ch1 - '0';
  43         break;
  44
  45       case 'd':                        /* decimal -- S-Lang extension */
  46         base = 10;
  47         i = 3;
  48         max = '9';
  49         num = 0;
  50         break;
  51
  52       case 'x':                        /* hex */
  53         base = 16;
  54         max = '9';
  55         i = 2;
  56         num = 0;
  57         break;
  58      }
  59
  60    while (i--)
  61      {
  62         ch1 = *p;
  63
  64         if ((ch1 <= max) && (ch1 >= '0'))
  65           {
  66              num = base * num + (ch1 - '0');
  67           }
  68         else if (base == 16)
  69           {
  70              ch1 |= 0x20;
  71              if ((ch1 < 'a') || ((ch1 > 'f'))) break;
  72              num = base * num + 10 + (ch1 - 'a');
  73           }
  74         else break;
  75         p++;
  76      }
  77
  78    *ch = (char) num;
  79    return p;
  80 }