lstrlen

Does the Win32 function lstrlen work on a array of characters the way VB's Len would work on a string. It seems to work ok, but I'm not too familiar with the different Win32 data types (it wants a LPCTSTR but I pass it a pointer to a char).

Here's the code I'm converting:

VB Code:

Dim strHTTP As String 'data buffer for HTTP header output
strHTTP = "Location: ./win2000.gif" & vbCrLf & vbCrLf
retval = WriteFile(STDOUT, ByVal strHTTP, Len(strHTTP), lngBytesWritten, ByVal 0&)

PHP Code:

---

char * chBuff; //data buffer
chBuff = "Location: ./win2000.gif\n\n";
retval = WriteFile(hStdOut, chBuff, lstrlen(chBuff), &dwBytesWritten, NULL); 


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PS - Does anyone know of a good reference for converting VB string functions (like Left$ or Space$) to the equivalent Win32 API functions (not ANSI C/C++ functions)?

Yes. It's there so you don't have to include the C or C++ Runtime Library if you need strlen.

LPCTSTR = const TCHAR* - TCHAR is normally char unless you're compiling for Unicode.

If you want things like Left$ or Mid$ it's usually easiest to use the standard library string class. However, if you don't mind messing around with buffers it isn't too hard to do.

lstrlen is already 'cast' to the right datatype, plus it's an api.

strlen is ansi C; it returns size_t, an unsigned integer. You have two choices; one calls the same api from embedded code, one the api directly. lstrlen is therefore generally faster under Windows.

PHP Code:

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char buf[100];
// A:

for (int i = 0;i< (int) strlen(buf);i++) { do something;}

// B:

for (int i = 0;i< lstrlen(buf); i++) {do the same thing;} 


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These are the same, except that lstrlen is not portable.

There's no speed difference in them. The library version does a loop through the string itself. Plus you don't need to cast size_t, since it's usually int.

Ok, thanks.

I'm actually trying to avoid library functions and stick with the API, to further my understanding of it.

I think what might be confusing me is the way Windows has ANSI or UNICODE string types. I'll have to read up on it when I get a chance.

Until you understand them, don't bother and anything that takes LPCSTR or LPCTSTR, pass char*. If it specifically has a W in it (like LPWSTR, LPCWSTR) then ask about it then and I'll give you some pointers (*cough*...sorry ;))

FWIW -
this generates a compiler warning:

for(int i = 0;i<strlen(str);i++)

unsigned and signed mismatch

this does not generate a compiler warning

for (int i = o;i<lstrlen(str);i++)

size_t is really UINT and int is signed. will definitely cause problems if you mix 'n' match types. It's a no-no.