Thread: Editing a text file

  1. #1
    Registered User
    Join Date
    Jan 2006

    Editing a text file

    I just started learning C++ not long ago, and has been stucked at this problem for quite sometimes.

    I have this text file which keep the records of cars.

    00001 Toyota Camry
    00002 Nissan Sunny
    00003 Honda Accord
    and so on

    The problem is when i use ofstream class and try to make a modification to the line that i want to do a lazy deletion.

    00002 Nissan Sunny -> xxxxxxxxxxxxxx (to indicate that this record is not a valid record)

    00001 Toyota Camry
    00003 Honda Accord
    and so on

    I ended up with file that has only the modification line and the rest was erased.


    I am using a fixed length record so i do know which byte to start the modification and where to stop.

            ofstream ofile;"test.txt, ios::out);
    	ofile.write("xxxxxxxxxxxxxx", 10 :confused: );
    this is something that similar to the code that exists in my program.

    in summary: how do i modify a part of a text file without erasing the rest of the content. Thank you in advance, I cannot proceed with the homework if i cant solve this confusion.
    Last edited by chimpanzee; 01-21-2006 at 06:51 AM.

  2. #2
    Registered User
    Join Date
    Aug 2005
    1,267"test.txt, ios::out | ios::ate);

  3. #3
    Frequently Quite Prolix dwks's Avatar
    Join Date
    Apr 2005
    Your original code opened your file for write, truncuating the file (making its size zero):
    Code:"test.txt, ios::out);
    AD's code will open the file for append, which doesn't erase the file.

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  4. #4
    Registered User
    Join Date
    Jan 2006
    Thanks a million guys. Really appreciate ur help

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