C++ :: File Save Routine - Blank Records In Module
Jul 10, 2013
I have faced a strange problem in File Save Routine. I have written a module to save data to binary file . I have designed a structure and put information in that and save it to file . I save multiple such records one after other. I use fwrite , fflush instructions.
The module is working fine. I have saved near about 35 such files. But in one file , the module has saved Blank Records. The file size if perfect but the file is totally blank. It has happened for only one file but need to know the reason.
I am trying to develop a GUI using MFC, but I am having trouble using CFiledialog to save a file. The problem is, the file is not getting saved to the folder when I use the CFiledialog. Below is the code I am using.
I wrote a program to compress a file with gzip, which works fine. I also wrote a program to decompress the gzip file, which runs but outputs a blank file.
Is this the right codes for deleting a recoed on the text file.
void dlte(){ string line, recorddate; cout << "Please Enter the date of record you want to delete: "; cin >> recorddate; ifstream myfile; ofstream temp; myfile.open("herald.txt");
I have to ask the user if they want to delete any records. The user can enter -1 to finish deleting records. I have to write the remaining records in an output file. So, i have this, but
1) it doesn't let me enter more than 1 id, and 2) it doesn't output anything to my output.txt.
records.txt 6 123 Jose Garcia 99 345 Luis Garcia 87 234 Jazlyn Soriano 79 456 Carter Sander 95 567 Natalia Soto 67 789 Isabel Santana 80
#include <iostream> #include <fstream> #include <cstdlib> #include <string> using namespace std; class Student { private: int id;
I have to ask the user if they want to delete any records. The user can enter -1 to finish deleting records. I have to write the remaining records in an output file. I have this, but 1) it doesn't let me enter more than 1 id, and 2 it doesnt output anything to my output.txt.
records.txt 6 123 Jose Garcia 99 345 Luis Garcia 87 234 Jazlyn Soriano 79 456 Carter Sander 95 567 Natalia Soto 67 789 Isabel Santana 80
Code: #include <iostream> #include <fstream> #include <cstdlib> #include <string> using namespace std; class Student { private: int id; string firstName;
My size of binary file is 1920 KB and my struct size is 124 kb. now to find number of records in file I divided 1920/124 and it gives me 15.4.... do I add 1 to 15.4 and make it 16 or do i take it as 15?
i have this program that i am undertaking.....this project needs to store customer details, edit them and delete them...now i am facing the problem of deriving a code to edit those details...
MY CODE
HTML Code: #include <fstream> #include <iostream> #include <string> using namespace std; int main () { int choice [1]; string name;
The program will prompt the user to enter a every student's first and last name, major ( of 4 choices CMPS MATH PHYSICS or EECE ), and grade. it's agreed that the professor will enter the name NoMore to stop the entry.
the program willl then store the info in a txt file. after closing the input file, the program will open it again read the records one at a time until end of file, and do some statistics including: highest grade, average grade, and highest average by major.
I'm making a small MFC module that should generate a report (formatted using HTML) and then display it for a user on schedule at 8:30 AM every day. Pretty straightforward stuff.
I compose my report and then save it as a local HTML file in the CSIDL_APPDATA folder. I then use the following calls to display it using the default web browser (Internet Explorer in this case):
Code: //Error checks are omitted for brevity CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE); ShellExecute(NULL, NULL, strSaveFileTo, NULL, NULL, SW_SHOWNORMAL);
This module is run on schedule from the Task Scheduler. (The task is set up to run when a user is logged on, which is all the time for that PC. It is never turned off, put to sleep, etc. That computer has only one user that is never logged off either.)
This works perfectly fine when I test it by setting the task a minute or so in the future. But when the actual task is supposed to run at 8:30 AM, when the user wakes the screen all they see is a blank Internet Explorer page. (Note that if someone refreshes that page by hitting F5, only then my report is shown on the screen.)
So I started looking into it:
1) I checked that the file is properly saved (before calling ShellExecute) by reading it back and by comparing it with the original HTML markup that I saved earlier. It's all correct there.
2) I then checked the power saving options. That computer is set up to show screensaver after 5 minutes and to turn off screen after 25 minutes.
3) The web browser that causes this issue is IE version 11, with the latest updates installed. The operating system is Windows 7 Professional.
And why is IE showing a blank page only when computer is running unattended?
I tried writing a cofactoring routine for n x n matrices and my code works but it shouldn't. Like, at all. But it does. Idk how and it's consistent.
Basically, my error is when assigning the sub-matrix for the cofactorization method I'm using from here :
Mathwords: Cofactor Matrix
My assignment routine should not work for the sub-matrix because of how I address the rows. under is always 0 and yet it'll assign values to the proper row. Idk how, it's magic.
Code: #include <stdio.h> #include <stdlib.h> long double det(long double **x, int rank) { /* Determinant calculator routine */ /* We initialize the resulting determinant to zero */
The function should pass the square of the first input parameter and the cube of the second input parameter back to the calling routine. I thought I could use a recursion but its not going to work.
how to produce a period signal that lasts 0.100 ms that is 35% red and 65% green using a bi-colour LED and the timer module?
while(ReadTimer0() < (unsigned int)165)
Its using this: OpenTimer0(TIMER_INT_OFF & T0_SOURCE_INT & T0_16BIT & T0_PS_1_32);
So does that mean that the period signal is 165 * 32 * 4/32 = 660 = 66%? I really just need to know how to calculate the period signal to produce 35% red and 65% green..
In short I'm converting a floating point bilinear image resampling routine into one that only uses fixed point arithmetic. I've gotten rid of nearly all the floats now, in fact all but one and the results at the moment are in distinguishable from the floating point version. It's a maths issue really. Some pseudocode goes like this.
Code: for( int xx=0; xx<ow; xx++ ) { int_center = (ccx >> 16); int temp = xx * 2; for (j = int_center; j <= int_center + 1; j++)
[Code] ....
Where ccx is and integer error accumulator that gives me a scaled integer. Shifting down buy 16 gives me the relative pixel I need to be working on. The line just after where the inner loop begins is where I have the last remaining float. FILTER_FACTOR is essentially a percentage by which I scale the error accumulator to the correct amount.
For example.
ccx = 98303. Which is a value of 1.5 when shited down by 16 bits. Obviously I can shift it because it will round and I lose the precision. Lets say FILTER_FACTOR is 39321. Which is 60% of 1 (65535) So what I'd like to know is, is it possible to use the FILTER_FACTOR as an integer and do some fancy integer math to scale the result from (ccx - (j<<16)) by the representative amount that is FILTER_FACTOR. In this example 60%. Effectively getting 40% of (ccx - (j<<16)) At the moment FILTER_FACTOR is still a float and therefore 0.6, which of course works just fine.
Code: /*Currency Conv Control Module*/ #include <stdio.h> #include "currencyconv.h" /* defines constants, declares functions */ int main(void) {
float us_dollars; float currency; int user_input;
[Code] ....
This is $$ converter program I created that is split up over 3 files. It takes the users input in US Dollars and converts it to the currency selected. When executing the program I am encountering a small problem. It actually isn't converting anything and returns 0.00 dollars.
I would like for it to convert the amount entered into the currency selected. I would also like to add in the print statement the type of currency the user has selected.
I am in need to convert some C# code into C++ equivalences. But I don't want to spend the efforts to do so. Is there an handy way to convert an existing code of C# into C++ (unmanaged code)?
1st when i fill the things on form then saved in database after saving record when i want add another record it shows an error. after saving it saves new record refresh doesn't work
I'm having a little problem with std:fstream - in my program, the user selects the location of a file which I want to remember. So, I have something like this:
Code: std::string fileLocation; //Code here creates an 'open file' dialog box which lets the user choose which file to open. //The string 'fileLocation' now contains the path to the chosen file. std::ofstream prefs("prefs.txt"); if (prefs.is_open()) { prefs << fileLocation; prefs.close(); }
This works fine if the file chosen is in the same directory as the program, however, if they try to choose a directory outside of where the program is kept, it saves the text file into that directory instead of the same one as the program. So, it looks like outputting a directory into an ofstream actually changes the location to which the file is saved.
Is there a way to save the file directory to a text file using ofstream and still have the text file save in the same directory as the program?
How do you create a save file for a game, that is not a separate file? Specifically I am using code::blocks and sfml 2.1 to make a game and it saves to a text file at the moment. My problem is that it is very easy to modify the text file, and it is annoying to have to copy and paste several files if you want to use a copy of the game. I have a feeling that it may be to do with resource files, but I'm not exactly sure how to get these to work or whether you can modify them dynamically.
