common/my_strings.h

   1 /*
   2     EIBD eib bus access and management daemon
   3     Copyright (C) 2005-2010 Martin Koegler <mkoegler@auto.tuwien.ac.at>
   4
   5     This program is free software; you can redistribute it and/or modify
   6     it under the terms of the GNU General Public License as published by
   7     the Free Software Foundation; either version 2 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU General Public License for more details.
  14
  15     You should have received a copy of the GNU General Public License
  16     along with this program; if not, write to the Free Software
  17     Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18 */
  19
  20 #ifndef MY_STRING_H
  21 #define MY_STRING_H
  22
  23 #include <string.h>
  24
  25 /** implements a string */
  26 class String
  27 {
  28   /** content */
  29   char *data;
  30   /** length */
  31   unsigned len;
  32 public:
  33   /** free memory */
  34     virtual ~ String ()
  35   {
  36     if (data)
  37       delete[]data;
  38   }
  39
  40   /** initialize with the empty string */
  41   String ()
  42   {
  43     data = 0;
  44     len = 0;
  45   }
  46
  47   /** initialize with a string */
  48   String (const String & a)
  49   {
  50     len = a.len;
  51     if (len)
  52       {
  53         data = new char[len];
  54         memcpy (data, a.data, len);
  55       }
  56     else
  57       data = 0;
  58   }
  59   /** assign a String */
  60   const String & operator = (const String & a)
  61   {
  62     if (data)
  63       delete[]data;
  64     len = a.len;
  65     if (len)
  66       {
  67         data = new char[len];
  68         memcpy (data, a.data, len);
  69       }
  70     else
  71       data = 0;
  72     return a;
  73   }
  74
  75   /** initialize with a character constant */
  76   String (const char *msg)
  77   {
  78     if (msg)
  79       {
  80         len = strlen (msg) + 1;
  81         data = new char[len];
  82         strcpy (data, msg);
  83       }
  84     else
  85       {
  86         data = 0;
  87         len = 0;
  88       }
  89   }
  90
  91   /** assign a character constant */
  92   const String & operator = (const char *msg)
  93   {
  94     if (data)
  95       delete[]data;
  96     if (msg)
  97       {
  98         len = strlen (msg) + 1;
  99         data = new char[len];
 100         strcpy (data, msg);
 101       }
 102     else
 103       {
 104         data = 0;
 105         len = 0;
 106       }
 107     return *this;
 108   }
 109
 110   /** concats two strings*/
 111   String operator + (const String & a)
 112   {
 113     String b;
 114     if (!len)
 115       return a;
 116     if (!a.len)
 117       return *this;
 118     b.len = a.len + len - 1;
 119     if (b.len > 0)
 120       {
 121         b.data = new char[b.len];
 122         if (data)
 123           strcpy (b.data, data);
 124         else
 125           b.data[0] = 0;
 126         if (a.data)
 127           strcat (b.data, a.data);
 128       }
 129     return b;
 130   }
 131
 132   bool operator == (const String & a) const
 133   {
 134     if (!a.len && !len)
 135       return 1;
 136     if (a.len != len)
 137       return 0;
 138     return (!strcmp (data, a.data));
 139   }
 140
 141   bool operator!= (const String & a) const
 142   {
 143     return !(*this == a);
 144   }
 145
 146   /** returns the content as char* */
 147   const char *operator  () () const
 148   {
 149     return data;
 150   }
 151
 152 };
 153
 154 /** adds a text to a string */
 155 inline const String &
 156 operator += (String & a, const String b)
 157 {
 158   String c = a + b;
 159   return (a = c);
 160 }
 161
 162 #endif