Programming Forums - Is there a way to delete a line from a file?

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- - Is there a way to delete a line from a file? (http://www.programmingforums.org/showthread.php?t=10074)

myName

May 30th, 2006 5:36 AM

Is there a way to delete a line from a file?

Is there a way to delete a line from a text file?

int        posEndIdx;

        int        ipos=0;

        string sLine;

        string sKeyWord;

        const string sDelim ( "]" );



        try

        {

                fstream myInputFile("D:\\Logs\\CMS\\UnSended\\upload.text");

                        

                if( myInputFile.is_open() )

                {

                        while( !myInputFile.eof() )

                        {

                                getline(myInputFile, sLine);

                                

                                if(sLine.empty())

                                        continue;



                                posEndIdx = sLine.find_first_of(sDelim);

                                sKeyWord = sLine.substr( posEndIdx+1, (sLine.length() - (posEndIdx+1)) );

                                cout<<sKeyWord<<endl;



                                //*******delete the line*******

                        }



                        myInputFile.close();

                }

        }

        catch(...)

        {

                cout<<"Exception"<<endl;

        }

nnxion

May 30th, 2006 7:16 AM

You write back the whole file without the lines you don't want (i.e. you don't write those lines).

myName

May 30th, 2006 9:44 PM

oh yeah... is a good idea... thanks nnxion

DaWei

May 30th, 2006 10:33 PM

Actually, you can delete a line from a file and only have to write the (original) file from the point of deletion onward. Editing a file in place when you might put more back than you took out is where the problem arises. Easier then to just work with a temp, as nnxion suggests.

Serinth

May 31st, 2006 12:19 AM

I wonder if you could do that with a couple of system commands in linux? ie. cat and grep, only use the reverse of a grep.

andro

May 31st, 2006 12:23 AM

You mean like... grep -v ?

;)

Serinth

May 31st, 2006 12:38 AM

lol, i was sitting on windows so i didn't bother to man page it. Good to know :).

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