sys/arch/ia64/stand/common/interp_backslash.c

   1 /*      $NetBSD: interp_backslash.c,v 1.2 2006/04/22 07:58:53 cherry Exp $      */
   2
   3 /*-
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * Jordan K. Hubbard
  14  * 29 August 1998
  15  *
  16  * Routine for doing backslash elimination.
  17  */
  18
  19 #include <sys/cdefs.h>
  20 /* __FBSDID("$FreeBSD: src/sys/boot/common/interp_backslash.c,v 1.6 2003/08/25 23:30:41 obrien Exp $"); */
  21
  22 #include <lib/libsa/stand.h>
  23 #include <lib/libsa/loadfile.h>
  24 #include <lib/libkern/libkern.h>
  25
  26 #include "bootstrap.h"
  27
  28 #define DIGIT(x) (isdigit(x) ? (x) - '0' : islower(x) ? (x) + 10 - 'a' : (x) + 10 - 'A')
  29
  30 /*
  31  * backslash: Return malloc'd copy of str with all standard "backslash
  32  * processing" done on it.  Original can be free'd if desired.
  33  */
  34 char *
  35 backslash(char *str)
  36 {
  37     /*
  38      * Remove backslashes from the strings. Turn \040 etc. into a single
  39      * character (we allow eight bit values). Currently NUL is not
  40      * allowed.
  41      *
  42      * Turn "\n" and "\t" into '\n' and '\t' characters. Etc.
  43      *
  44      */
  45     char *new_str;
  46     int seenbs = 0;
  47     int i = 0;
  48
  49     if ((new_str = strdup(str)) == NULL)
  50         return NULL;
  51
  52     while (*str) {
  53         if (seenbs) {
  54             seenbs = 0;
  55             switch (*str) {
  56             case '\\':
  57                 new_str[i++] = '\\';
  58                 str++;
  59                 break;
  60
  61             /* preserve backslashed quotes, dollar signs */
  62             case '\'':
  63             case '"':
  64             case '$':
  65                 new_str[i++] = '\\';
  66                 new_str[i++] = *str++;
  67                 break;
  68
  69             case 'b':
  70                 new_str[i++] = '\b';
  71                 str++;
  72                 break;
  73
  74             case 'f':
  75                 new_str[i++] = '\f';
  76                 str++;
  77                 break;
  78
  79             case 'r':
  80                 new_str[i++] = '\r';
  81                 str++;
  82                 break;
  83
  84             case 'n':
  85                 new_str[i++] = '\n';
  86                 str++;
  87                 break;
  88
  89             case 's':
  90                 new_str[i++] = ' ';
  91                 str++;
  92                 break;
  93
  94             case 't':
  95                 new_str[i++] = '\t';
  96                 str++;
  97                 break;
  98
  99             case 'v':
 100                 new_str[i++] = '\13';
 101                 str++;
 102                 break;
 103
 104             case 'z':
 105                 str++;
 106                 break;
 107
 108             case '0': case '1': case '2': case '3': case '4':
 109             case '5': case '6': case '7': case '8': case '9': {
 110                 char val;
 111
 112                 /* Three digit octal constant? */
 113                 if (*str >= '0' && *str <= '3' &&
 114                     *(str + 1) >= '0' && *(str + 1) <= '7' &&
 115                     *(str + 2) >= '0' && *(str + 2) <= '7') {
 116
 117                     val = (DIGIT(*str) << 6) + (DIGIT(*(str + 1)) << 3) +
 118                         DIGIT(*(str + 2));
 119
 120                     /* Allow null value if user really wants to shoot
 121                        at feet, but beware! */
 122                     new_str[i++] = val;
 123                     str += 3;
 124                     break;
 125                 }
 126
 127                 /* One or two digit hex constant?
 128                  * If two are there they will both be taken.
 129                  * Use \z to split them up if this is not wanted.
 130                  */
 131                 if (*str == '0' &&
 132                     (*(str + 1) == 'x' || *(str + 1) == 'X') &&
 133                     isxdigit(*(str + 2))) {
 134                     val = DIGIT(*(str + 2));
 135                     if (isxdigit(*(str + 3))) {
 136                         val = (val << 4) + DIGIT(*(str + 3));
 137                         str += 4;
 138                     }
 139                     else
 140                         str += 3;
 141                     /* Yep, allow null value here too */
 142                     new_str[i++] = val;
 143                     break;
 144                 }
 145             }
 146             break;
 147
 148             default:
 149                 new_str[i++] = *str++;
 150                 break;
 151             }
 152         }
 153         else {
 154             if (*str == '\\') {
 155                 seenbs = 1;
 156                 str++;
 157             }
 158             else
 159                 new_str[i++] = *str++;
 160         }
 161     }
 162
 163     if (seenbs) {
 164         /*
 165          * The final character was a '\'. Put it in as a single backslash.
 166          */
 167         new_str[i++] = '\\';
 168     }
 169     new_str[i] = '\0';
 170     return new_str;
 171 }