Solved

Update records in file with fstream

Posted on 1998-06-08
1
298 Views
Last Modified: 2010-04-01
How can i update the records in file using c++ fstream
classes ( seekp and tellp ) ???? or is there a diffrent
method of doing this ???
0
Comment
Question by:sector
1 Comment
 
LVL 11

Accepted Solution

by:
alexo earned 20 total points
ID: 1165345
The istream class has the seekg() and tellg() methods for positioning the read pointer.
The ostream class has the seekp() and tellp() methods for positioning the write pointer.

Say you have these definitions:

    struct Record { ... };

    Record patish;
    fstream f("laflaf");

Say you want to read record #17:

    f.seekg(17 * sizeof Record, ios::beg) >> patish;

Say you want to write it into record #23:

    f.seekp(23 * sizeof Record, ios::beg) << patish;

tellg() and tellp() return the current read/write position which you can use in a single-argument versions of seekg() and seekp().

0

Featured Post

DevOps Toolchain Recommendations

Read this Gartner Research Note and discover how your IT organization can automate and optimize DevOps processes using a toolchain architecture.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Introduction This article is the first in a series of articles about the C/C++ Visual Studio Express debugger.  It provides a quick start guide in using the debugger. Part 2 focuses on additional topics in breakpoints.  Lastly, Part 3 focuses on th…
Container Orchestration platforms empower organizations to scale their apps at an exceptional rate. This is the reason numerous innovation-driven companies are moving apps to an appropriated datacenter wide platform that empowers them to scale at a …
The viewer will learn how to pass data into a function in C++. This is one step further in using functions. Instead of only printing text onto the console, the function will be able to perform calculations with argumentents given by the user.
The viewer will learn additional member functions of the vector class. Specifically, the capacity and swap member functions will be introduced.

770 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question