Re: reading string from a text file from vc++ without MFC support

From:
 rindam2002@yahoo.com
Newsgroups:
microsoft.public.vc.mfc
Date:
Tue, 19 Jun 2007 02:52:11 -0700
Message-ID:
<1182246731.126260.159650@q19g2000prn.googlegroups.com>
On Jun 17, 2:43 pm, MrAsm <m...@usa.com> wrote:

On Sat, 16 Jun 2007 23:11:11 -0700, rindam2...@yahoo.com wrote:

will U plz get me a code forreadingfileline by
line usingFILEstructure.


OK, I understand that you want to use C 'FILE*'.

my textfilewill be having random number of
data such as
      atlanta/123
      atlanta/greetings
      atlanta/double
      ............
      ............
      ....//random nuber of lines.
Now I need to read each line of thefileand save it into astring
variable and use this variable in the application.the problem here is


The problem is easy. You just need to open thefileusing _tfopen
(_tfopen is the Unicode-aware version of standard C fopen), read text
lines using _fgetts (the Unicode-aware version of standard C fgets),
until you reach end offile(use feof to test it) and close thefile
with fclose.

You read eachfileline into a temporary local buffer (TCHAR array of
maximum specified size) using _fgetts, and then you can store the line
you have just read in the old-style C buffer into a more modern robust
useful CString instance.

<CODE>
    CString fileName = _T("c:\\prova.txt");

    // Open thefileforreadingin text mode
   FILE*file= _tfopen( fileName, _T("rt"));
    // Iffile== NULL ... error

    // Maximum number of characters in a line
    static const int maxLineChars = 200;

    // This will store each line of text
    TCHAR line[ maxLineChars ];

    // Read line by line fromfile
    while ( ! feof(file) )
    {
        // Clear destination buffer
        ::ZeroMemory( line, sizeof(line) );

        // Read the line
        _fgetts( line, maxLineChars,file);

        // Now 'line' contains the line read fromfile.
        // Do your processing.
        // e.g.: You may store the read line into a CString
        CString strLine( line );

        // Process strLine...
        // DoLineProcessing( strLine );
        ...
    }

    // Close thefile
    fclose(file);
   file= NULL; // Avoid dangling references

</CODE>

that I dont know How many lines will thefilehave.


No problem: 'feof' function and 'while' statement help you here :)

MrAsm


Hi MrAsm
     Your code is good but there is one problem,If I do
MessageBox(strLine) after CString strLine( line),then I am getting one
blank Message box after reading all the lines.Means if the file is
having one line,then first messagebox is displaying the line value and
one more messagebox is coming which is blank.I dont want this blank
messagebox.Plz help me to solve this problem with code.again thanks a
lot for all ur help.

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