Digg
del.icio.us
Newsvine
Facebook
Google
LinkedIn
MySpace
Reddit
Slashdot
StumbleUpon
Technorati
Twitter
Windows Live
YahooBuzz
FriendFeedA class for double zeroterminated strings
Posted
by Gert Rijs
on August 22nd, 1998
There are several win32 functions that require the use of a string with embedded
NULLs and are terminated with an extra NULL (i will call them DZ strings for short).
An example of such a DZ string: "part1\0part2\0part3\0\0".
To name just a few of functions that work with DZ strings:
- GetPrivateProfileSection
- WritePrivateProfileSection
- SQLConfigDataSource
The CString class could be used to manipulate them, but you must be carefull not to call the non-DZ-aware CString-methods (such as Right(), Mid(), Left(), Replace() and Find()).
I decided to create a class that helps constructing and parsing those DZ strings. The class is called CDoubleZeroString and is not derived from CString.
An example how to use this class:
CDoubleZeroString dz;
dz.Add("a=1"); // add a zeroterminated 'part'
dz.Add("b=2");
dz.Add("c=3");
// operator(const char*) will return "a=1\0b=2\0c=3\0\0"
WritePrivateProfileSection("humbug", dz, ".\\humbug.ini");
char buffer[1024];
GetPrivateProfileSection("humbug", buffer, sizeof buffer, ".\\humbug.ini");
// cleanup dz
dz.Empty();
// AddDoubleZero will parse buffer
dz.AddDoubleZero(buffer);
// print the outcome
for(int i=0;i<dz.GetCount();i++)
cout << dz.Get(i) << endl;
CString test = dz;
cout << "cstring " << test << endl;
This will show the following output:a=1
b=2
c=3
cstring a=1
The CString test will only copy the first substring when it is constructed...
If you want to implement this using CString you would have to do something like:
CString dz("a=1\0" "b=2\0" "c=3\0" "\0", 13);
// or some prefer:
CString dz("a=1@b=2@c=3@@");
int pos;
// note that you MUST use ReverseFind (not Find) for this to work
while((pos=dz.ReverseFind("@"))!=-1)
dz.SetAt(pos, '\0');
Last updated: August 17, 1998
Comments
hi
Posted by lexito on 05/23/2008 11:04amOr you could just use std::string...
Posted by Legacy on 08/09/2002 12:00amOriginally posted by: DrPizza
... which is a counted string, not a null-terminated string.
ReplyHow about a C version?
Posted by Legacy on 11/21/2000 12:00amOriginally posted by: David Duncan Ross Palmer
Are you a C++ programmer who hates C?
If not how about a C version of this, that would be useful.
For example a structure of pointers to C functions and of course manually passing >this< pointers. Or alternatively non-OOP altogether such as a library of functions for dealing with these types of strings.
Reply