lib-src/strings/charesc.cc

   1 //////////////////////////////////////////////////////////////////////////////
   2 // NOTICE:
   3 //
   4 // ADLib, Prop and their related set of tools and documentation are in the
   5 // public domain.   The author(s) of this software reserve no copyrights on
   6 // the source code and any code generated using the tools.  You are encouraged
   7 // to use ADLib and Prop to develop software, in both academic and commercial
   8 // settings, and are free to incorporate any part of ADLib and Prop into
   9 // your programs.
  10 //
  11 // Although you are under no obligation to do so, we strongly recommend that
  12 // you give away all software developed using our tools.
  13 //
  14 // We also ask that credit be given to us when ADLib and/or Prop are used in
  15 // your programs, and that this notice be preserved intact in all the source
  16 // code.
  17 //
  18 // This software is still under development and we welcome any suggestions
  19 // and help from the users.
  20 //
  21 // Allen Leung
  22 // 1994
  23 //////////////////////////////////////////////////////////////////////////////
  24
  25 #include <ctype.h>
  26 #include <AD/strings/charesc.h>
  27
  28 char * quote_string (char * buf, const char * s)
  29 {   while (*s)
  30     {  char c;
  31        s = parse_char(s,c);
  32        buf = print_char(buf,c);
  33     }
  34     *buf = '\0';
  35     return buf;
  36 }
  37
  38 const char * parse_char(const char * s, char& c)
  39 {  if (*s == '\\') {
  40       s++;
  41       switch (*s) {
  42          case '0': case '1':
  43          {  char ch; int count;
  44             for (ch = 0, count = 0; *s >= '0' && *s <= '7' && count < 3; s++, count++)
  45                ch = ch * 8 + *s - '0';
  46             c = ch; return s;
  47          }
  48          case 'n': c = '\n'; break;
  49          case 't': c = '\t'; break;
  50          case 'x':
  51          case 'X':
  52          {  int digit1;
  53             int digit2;
  54             s++;
  55             if (isdigit(*s)) digit1 = *s - '0';
  56             else if (*s >= 'a' && *s <= 'f') digit1 = *s - 'a' + 10;
  57             else if (*s >= 'A' && *s <= 'F') digit1 = *s - 'A' + 10;
  58             else digit1 = 0;
  59             s++;
  60             if (isdigit(*s)) digit2 = *s - '0';
  61             else if (*s >= 'a' && *s <= 'f') digit2 = *s - 'a' + 10;
  62             else if (*s >= 'A' && *s <= 'F') digit2 = *s - 'A' + 10;
  63             else digit2 = 0;
  64             c = digit1 * 16 + digit2;
  65             return s+1;
  66          } break;
  67          default: c = *s;
  68       }
  69    } else c = *s;
  70    return s + 1;
  71 }
  72
  73 char * print_char(char * s, char c)
  74 {
  75    if (c == '\n') {
  76       *s++ = '\\'; *s++ = 'n'; *s = '\0'; return s;
  77    } else if (c == '\t') {
  78       *s++ = '\\'; *s++ = 't'; *s = '\0'; return s;
  79    } else if (c == '\'' || c == '\"' || c == '\\') {
  80       *s++ = '\\'; *s++ = c; *s= '\0'; return s;
  81    } else if (isprint(c)) {
  82       *s++ = c; *s = '\0'; return s;
  83    } else {
  84       unsigned char ch = c;
  85       s[0] = '\\';
  86       s[1] = ch / 64 + '0';
  87       s[2] = (ch / 8) % 8 + '0';
  88       s[3] = ch % 8 + '0';
  89       s[4] = '\0';
  90       return s + 4;
  91    }
  92 }
  93
  94 const char * print_char(char c)
  95 {  static char buf[10];
  96    print_char(buf,c);
  97    return buf;
  98 }