mhl/escape.h

   1 #ifndef __MHL_SHELL_ESCAPE_H
   2 #define __MHL_SHELL_ESCAPE_H
   3
   4 /* Micro helper library: shell escaping functions */
   5
   6 #include <string.h>
   7 #include <stdlib.h>
   8
   9 #define mhl_shell_escape_toesc(x)       \
  10     (((x)==' ')||((x)=='!')||((x)=='#')||((x)=='$')||((x)=='%')||       \
  11      ((x)=='(')||((x)==')')||((x)=='\'')||((x)=='&')||((x)=='~')||      \
  12      ((x)=='{')||((x)=='}')||((x)=='[')||((x)==']')||((x)=='`')||       \
  13      ((x)=='?')||((x)=='|')||((x)=='<')||((x)=='>')||((x)==';')||       \
  14      ((x)=='*')||((x)=='\\')||((x)=='"'))
  15
  16 #define mhl_shell_escape_nottoesc(x)    \
  17     (((x)!=0) && (!mhl_shell_escape_toesc((x))))
  18
  19 static inline char* mhl_shell_escape_dup(const char* src)
  20 {
  21     if ((src==NULL)||(!(*src)))
  22         return strdup("");
  23
  24     char* buffer = calloc(1, strlen(src)*2+2);
  25     char* ptr = buffer;
  26
  27     /* look for the first char to escape */
  28     while (1)
  29     {
  30         char c;
  31         /* copy over all chars not to escape */
  32         while ((c=(*src)) && mhl_shell_escape_nottoesc(c))
  33         {
  34             *ptr = c;
  35             ptr++;
  36             src++;
  37         }
  38
  39         /* at this point we either have an \0 or an char to escape */
  40         if (!c)
  41             return buffer;
  42
  43         *ptr = '\\';
  44         ptr++;
  45         *ptr = c;
  46         ptr++;
  47         src++;
  48     }
  49 }
  50
  51 /* shell-unescape within a given buffer (writing to it!) */
  52 static inline char* mhl_shell_unescape_buf(char* text)
  53 {
  54     if (!text)
  55         return NULL;
  56
  57     // look for the first \ - that's quick skipover if there's nothing to escape
  58     char* readptr = text;
  59     while ((*readptr) && ((*readptr)!='\\'))    readptr++;
  60     if (!(*readptr)) return text;
  61
  62     // if we're here, we're standing on the first '\'
  63     char* writeptr = readptr;
  64     char c;
  65     while ((c = *readptr))
  66     {
  67         if (c=='\\')
  68         {
  69             readptr++;
  70             switch ((c = *readptr))
  71             {
  72                 case 'n':       (*writeptr) = '\n'; writeptr++; break;
  73                 case 'r':       (*writeptr) = '\r'; writeptr++; break;
  74                 case 't':       (*writeptr) = '\t'; writeptr++; break;
  75
  76                 case ' ':
  77                 case '\\':
  78                 case '#':
  79                 case '$':
  80                 case '%':
  81                 case '(':
  82                 case ')':
  83                 case '[':
  84                 case ']':
  85                 case '{':
  86                 case '}':
  87                 case '<':
  88                 case '>':
  89                 case '!':
  90                 case '*':
  91                 case '?':
  92                 case '~':
  93                 case '`':
  94                 case '"':
  95                 case ';':
  96                 default:
  97                     (*writeptr) = c; writeptr++; break;
  98             }
  99         }
 100         else    // got a normal character
 101         {
 102             (*writeptr) = *readptr;
 103             writeptr++;
 104         }
 105         readptr++;
 106     }
 107     *writeptr = 0;
 108
 109     return text;
 110 }
 111
 112 #endif