dcsimg

Login | Register

CString instead of LPCSTR

Posted by Jon Zyzyck on April 16th, 2002

WEBINAR:
On-Demand

Application Security Testing: An Integral Part of DevOps


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

  • You must have javascript enabled in order to post comments.

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  • Your email address will not be published.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

Top White Papers and Webcasts

  • The Challenges and Rewards of Big Data
    As all sorts of data becomes available for storage, analysis and retrieval - so called 'Big Data' - there are potentially huge benefits, but equally huge challenges...
  • Turning Big Data into Useful Information
    The agile organization needs knowledge to act on, quickly and effectively. Though many organizations are clamouring for "Big Data", not nearly as many know what to do with it...
  • The Challenges of Cloud Integration
    Cloud-based integration solutions can be confusing. Adding to the confusion are the multiple ways IT departments can deliver such integration...

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date
×
We have made updates to our Privacy Policy to reflect the implementation of the General Data Protection Regulation.