Hmmm... Comparison Troubles...

[Inquirer]

I have been working in the registry for awhile now, not really reading anything though. OF course, when i do i run into trouble. Below is the code i am using, with comments where i get the problems (i think). The registry code is not the problem. It is comparing the return values with predetermined values that i hit the walls.

  HKEY hKey;
  if (!RegOpenKeyEx(HKEY_LOCAL_MACHINE, TEXT("SOFTWARE\\Native\\SaveAll"), 0, KEY_QUERY_VALUE, &hKey)) return false;

  unsigned char buffer[256]; // It puts the data here...
  unsigned char yes[256] = "Yes";  // What i am going to compare with...
  unsigned long datatype;
  unsigned long bufferlength = sizeof(buffer);

  RegQueryValueEx(hKey, "Active", NULL, &datatype, buffer, &bufferlength);
 
  RegCloseKey(hKey);

  if (buffer == yes) return true;  // How do i compare these?? This is where i get the problems.
  return false;

Even when the data appears to be the same, it still returns false.

[Hammer]

>>if (buffer == yes)
Classic mistake, I'm afraid.

Look up strcmp() for comparing strings.

[Eibro]

if (std::stricmp(buffer, "Yes") == 0)

Remember to include <string>
Edit:: Beaten again...

[Inquirer]

the problem though, is that the buffer is an unsigned char *.

I get compiler complaints every time, with all of the strcmp functions i have tried.

Ex.

42 main.cpp
 passing `unsigned char *' as argument 1 of `stricmp(const char *, const char *)' changes signedness

42 main.cpp
 passing `unsigned char *' as argument 1 of `strcmp(const char *, const char *)' changes signedness


42 main.cpp
 passing `unsigned char *' as argument 2 of `strcmp(const char *, const char *)' changes signedness

[Eibro]

Try

if (std::stricmp(reinterpret_cast<const char *>(buffer), "Yes") == 0)

[Sebastiani]

So cast it.

if(stricmp((char*)buffer, "yes"))...

[moi]

Originally posted by Inquirer
the problem though, is that the buffer is an unsigned char *.

I get compiler complaints every time, with all of the strcmp functions i have tried.

Ex.

42 main.cpp
 passing `unsigned char *' as argument 1 of `stricmp(const char *, const char *)' changes signedness

42 main.cpp
 passing `unsigned char *' as argument 1 of `strcmp(const char *, const char *)' changes signedness


42 main.cpp
 passing `unsigned char *' as argument 2 of `strcmp(const char *, const char *)' changes signedness

is there any reason the buffer needs to be unsigned char? as a general rule, you should just use char when working with strings, not signed or unsigned, because then the target system can choose whatever is fastest/easiest to work with for it

[Inquirer]

*bump*

If anyone cares, i found the source of my problem. I was thinking that strcmp returned a true value if it matches, but in actuality, it returns a zero. If it doesn't match, then it returns the character position thta doesn't. Thanks for your help and suggestions. This solved my whole problem

~Inquirer