modules/src/string/str2bts.c

   1 /* $Id: str2bts.c,v 1.6 1994/06/24 11:22:44 ceriel Exp $ */
   2 /*
   3  * (c) copyright 1987 by the Vrije Universiteit, Amsterdam, The Netherlands.
   4  * See the copyright notice in the ACK home directory, in the file "Copyright".
   5  */
   6 /* str2bts -- (1985, EHB)
   7 */
   8
   9 #include "ack_string.h"
  10
  11 static
  12 is_oct(c)
  13         char c;
  14 {
  15         return ((unsigned int)(c-'0') <= ('7'-'0'));
  16 }
  17
  18 /*      str2bts() strips the escaped characters of a
  19         string and replaces them by the ascii characters they stand for.
  20         The ascii length of the resulting string is returned, including the
  21         terminating null-character.
  22 */
  23 char *
  24 str2bts(str, bts, pn)
  25         register char *str;
  26         char *bts;
  27         int *pn;
  28 {
  29         register char *t = bts;
  30
  31         while (*str) {
  32                 if (*str == '\\') {
  33                         switch (*++str) {
  34                         case 'b':
  35                                 *t++ = '\b';
  36                                 str++;
  37                                 break;
  38                         case 'f':
  39                                 *t++ = '\f';
  40                                 str++;
  41                                 break;
  42                         case 'n':
  43                                 *t++ = '\n';
  44                                 str++;
  45                                 break;
  46                         case 'r':
  47                                 *t++ = '\r';
  48                                 str++;
  49                                 break;
  50                         case 't':
  51                                 *t++ = '\t';
  52                                 str++;
  53                                 break;
  54                         default:
  55                                 if (is_oct(*str)) {
  56                                         register cnt = 0, oct = 0;
  57
  58                                         do
  59                                                 oct = oct * 8 + *str - '0';
  60                                         while (is_oct(*++str) && ++cnt < 3);
  61                                         *t++ = (char) oct;
  62                                         break;
  63                                 }
  64                                 *t++ = *str++;
  65                                 break;
  66                         }
  67                 }
  68                 else
  69                         *t++ = *str++;
  70         }
  71         *t = '\0';      /* don't forget this one !!!    */
  72         *pn = t - bts + 1;
  73         return bts;
  74 }