Problem: Reading and editing text file data

I have a text file having data something like:

Quote:

---

ww1
ww2
ww3
ww4

---

I want to search for a particular string in this file, so i am reading this file. When the word is found say "ww3" , i wish to edit that entry to something like $$ww3 or ( add anything). I tried using pos() and seek(), but it's deleting all text data from file leaving one or two chars.

I would like to know some way to do this. Please help.

Thanks in advance.

Rewrite the entire file:

(Psuedocode, you would use QFile for this)

Code:

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while (!eof(file))
{
   str = readlinefromfile();
   if (str == "ww3") writelinetofile("$$ww3"); else writelinetofile(str);
}

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Thanks squidge! But, i am using ReadWrite mode in QFile, which is not rewriting the whole file rather it is writing the desired content at the end of file. Something like this...

Quote:

---

Input file:

bb1
bb2
bb3


o/p getting:

bb1
bb2
bb3
bb1
$$bb2
bb3

desired o/p:
only:

bb1
$$bb2
bb3

---

Code:

---

QFile file_bl1("E:\\SMS\\dSenderBlackList.txt");
            file_bl1.open(QIODevice::ReadWrite | QIODevice::Text);
            file_bl1.reset();
            QTextStream bl_in1(&file_bl1);
            QString bl_line1;
            bl_line1 = bl_in1.readLine();
            while(!bl_line1.isNull())
            {
 
                if(str==bl_line1)
                {
                    bl_in1<<"$$"<<str<<"\n";
                }
                else
                {
                    bl_in1<<bl_line1<<"\n";
 
                }
                bl_line1 = bl_in1.readLine();
 
            }

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I am trying , but it would be good if someone can help me in figuring out how to perform aforementioned. Thanks.

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Added after 29 minutes:

Thanks Squidge!! PROBLEM is solved. Just took a different pointer for writing.