CString instead of LPCSTR

A simple routine to allow CString formatted strings to be used wherever a regular LPCSTR would be used, without needing to define a CString (ie, dynamically created and formatted LPCSTR strings)

.

Environment: VC6 SP4

Well, I've seen other people asking for a class like this, and I sure wanted one, so I finally wrote one.

Suppose you want to call a routine with a dynamically constructed LPCSTR. You would call it like this:

SampleRoutine( (LPCSTR) csFMT(
                  "Sample dynamic string count(%d) name(%s)",
                  nAnInteger,
                  szAZeroTerminatedString));

The Microsoft CString class provides a Format member routine which provides sprintf-type formatting, without the need to allocate a buffer. The class CString automatically calculates the size of the buffer required, and allocates it. A CString variable, however, must first be declared. This routine allows the CString Format member routine to be used, without needing to declare a CString.

Here is the sample code without using the "csFmt" routine:

  CString csTemp;
  CsTemp.Format("Sample dynamic string count(%d) name(%s)",
                nAnInteger, szAZeroTerminatedString);
  SampleRoutine((LPCSTR) csTemp);

This method doesn't require any subclassing, and is only a short < 10 line routine.

CString csFMT(LPCSTR lpszFormat, ...)
{
    CString csStr;

    va_list argList;
    va_start(argList, lpszFormat);
    csStr.FormatV(lpszFormat, argList);
    return csStr;
}

Downloads

You can cut & paste code from above.



Comments

  • If only Format whould ??

    Posted by Legacy on 06/04/2002 12:00am

    Originally posted by: Boaz Harrosh

    If CString::Format was defined as
    CString& AFX_CDECL Format(LPCTSTR lpszFormat, ...);
    and not:
    void AFX_CDECL Format(LPCTSTR lpszFormat, ...);

    than we could just do:
    cout << (LPCSTR)CString().Format("%s" ,"yes it works this way") ;


    A constructor is callable in C++. It is just like a type cast.

    Reply
  • Another way

    Posted by Legacy on 04/17/2002 12:00am

    Originally posted by: Mathieu Fr.

    You can also do such a thing. No cstring. no alloc.
    
    Of course there are restrictions due to the static buffer, but SPEED matters sometimes (and mem alloc too) !

    LPCSTR poil(LPCSTR lpszFormat, ...)
    {
    const char buff[1000];
    va_list argList;
    va_start(argList, lpszFormat);
    vsprintf( buff, lpszFormat, argList );
    return buff;
    }

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: October 29, 2014 @ 11:00 a.m. ET / 8:00 a.m. PT Are you interested in building a cognitive application using the power of IBM Watson? Need a platform that provides speed and ease for rapidly deploying this application? Join Chris Madison, Watson Solution Architect, as he walks through the process of building a Watson powered application on IBM Bluemix. Chris will talk about the new Watson Services just released on IBM bluemix, but more importantly he will do a step by step cognitive …

  • Businesses are moving more and more of their customer transactions to the web. Security is understandably a top concern as online transactions increase, so it is important to make sure your electronic signature provider meets the highest security standards. That means more than simply passing a security audit or obtaining a certification. This white paper provides recommendations for taking a broader view of e-signature security, and answers key questions that help identify the security requirements against …

Most Popular Programming Stories

More for Developers

Latest Developer Headlines

RSS Feeds