why I'm giving "Access violation reading location 0x336827B8" and also I was able to read my data but it's giving me weird stuff. I want to write the sorted grades and the average in a new disk file. so here's my code so far here's my code
#include "stdafx.h"
#include <iostream>
#include <fstream>
#include <string>
#include <iomanip>
using namespace std;
int avg(int sum, int size);
void swap(int *, int *);
[code]....
I have to write a program that sorts names and grades from a file and output them to another.
For example:
Name: Peter Parker
Exam 1: 95
Exam 2: 90.625
Exam 3: 91.20
Name: Mary Smith
Exam 1: 65
Exam 2: 79.1234
Exam 3: 70.24
Becomes something like this in the output file:
Name: Parker, Peter
Average Score: 92.28
Grade: A
Name: Smith, Mary
Average Score: 71.45
Grade: C
I know I'm supposed to read the whole file, but I'm getting really confused on how to take the name of each student separately without recording Exam 1, 2, and 3. I'll be able to do the average score and grade on my own.
I'm messing around with reading and writing files. The first file creates a small txt file. Simple enough
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main(){
string name;
string desc;
[Code] ....
It does what it should. It creates a text file "items.txt" .... It reads as such:
dagger,a dagger,15,10,0,1,3,1,0,0,0,1,0,0,0,0,0,1
The second file is meant to read the file and place the data back into the variables. This happens, but the data crams itself into the first variable, and the rest of them collect the trash that's in memory.
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
int main() {
string name,desc;
[Code ....
I need to get "dagger" into name, "a dagger" into description, and each value with their perspective variable. I'm sure I need some type of "separator". Hopefully I can use the comma. Before it's over, I will have about a hundred items that will need to be read into a class of items.
program that I am working on. I want to use fgets() in my program so I could handle multiple words from a text(to be able to handle spaces). I get a weird result when running the program.
Code: #include <stdio.h>
#include <stdlib.h>
//#include "kim.h"
#include <string.h>
[code]....
How to write the code for this with the following requirements:
download the text file weblog.txt
This file is an Apache web log taken from the web server for St. Mary's University. When a visitor goes to their web site, the visitor's browser makes a request to the web server to view a web page, which is a file residing on the server. Each time a page is requested by a browser, the web server records information about that request. This weblog.txt holds the details of some of those requests.
Create a non-member function to read each line of the web log file. This function must do error checking to ensure that the file is opened successfully, otherwise it must provide a message like "file not available" to the user.
Each line should then be stored in a vector such that the first element of the vector is the first line of the web log file. Because each element will hold an entire line from the file, the vector should be declared as a vector of strings.
Note: You must declare the vector in a function.
Create another non-member function to sort the contents of the vector. Make sure to pass the vector by reference or your sort will disappear when the function ends! Use the sort function with #include <algorithm> to do the sort; you do not have to write your own sort algorithm.
Create one more non-member function to write the contents of the vector to a file. Each element should be on its own line in the new file. The contents of the new file should look like the original input file once your program completes, but in sorted order.
Create a main function that calls all of your non-member functions.
I am using the code below to write a single instance of object "Employee" to a file in Binary mode. The write part seems to work fine, however when I try to read the single employee object from the file into memory I get a double free or corruption error.
I think this has to do with the fact that I am using a string data member in the Employee class but I don't understand what is going wrong. I have read that strings can vary in length and use dynamic memory allocation but if I write a single employee object to a file with data member 'name' equal to "John", it should be the exact same size when I read it back in right?
The code below works with no issues when I omit the string data member. Why is that? Where is the memory for the string object being "double released" when I read the employee object back into memory from the file?
I am using Linux Mint 15, Eclipse June and GCC 4.7.3 with the -std=c++11 option.
#include <iostream>
#include <fstream>
#include <string>
[Code].....
I am having problems either writing data to a binary file or reading from the file. Through the process of elimination I am posting the code where the data is written to file to see if I can eliminate that as an option. I know the data is being processed correctly because, through the use of another function, I can view the data.
I also know that fwrite must be including some padding because the file size ends up being 576 bytes after it is written instead of 540 bytes (the size it would be if no padding is used). Here is my struct:
Code:
typedef struct {
char teams[25];
float wins;
float losses;
float pct;
int runsScored;
int runsAgainst;
} STATISTICS;
Here is where I initialize it:
Code:
STATISTICS stats[12] = {
{"Anaheim Arrays", 0.0, 0.0, .000, 0, 0},
{"Pittsburg Pointers", 0.0, 0.0, .000, 0, 0},
{"Indianapolis Integers", 0.0, 0.0, .000, 0, 0},
[Code] ....
And here is the function that writes my data. The sA array is only used to change the scheduled games based on the variable week.
Code:
void schedule(STATISTICS stats[]) {
FILE *f;
int sA[12], week = 0, runsPerGameA = 0, runsPerGameB = 0, runsAgainstA = 0, runsAgainstB = 0;
int index, a = 0, b = 1, i = 0;
[Code] .....
I am writing a double number in Binary format to the console of program A (in FORTRAN) with the following code:
Code:
REAL*8 A
A = 12.54
INQUIRE(6, name = xstring)
OPEN(1,file=xstring, access='stream',action='write')
WRITE (1) A
CLOSE(1)
And trying to read that number by program B (in C++) which is connected to program A by anonymous pipes. Following is the reading part of program B:
Code:
#define BUF_SIZE 5000
BOOL bSuccess = FALSE;
char Buf[BUF_SIZE];
DWORD dwRead;
for (;;) {
bSuccess = ReadFile( V_hChildStd_OUT_Rd, Buf, BUF_SIZE, &dwRead, NULL);
if( ! bSuccess || dwRead == 0 ) break;
}
Note: V_hChildStd_OUT_Rd is a handle to the output of program A.
After running the program although bSuccess becomes TRUE, Buf array does not include the number (12.54) that I am expecting. If I do the same process without using the binary format it works fine and I can read the number. I know somethings wrong with the writing or reading of binary data but I do not know what it is.
How to read and write an arbitrary number of bits from/to a file stream.
For instance, how to repeatedly read 9 bits from a file, then change to 10 bits, then 11 bits, and so on?
Obviously one way is by doing a lot of bit shifting, and masking. But honestly, I'm too dumb to get it right. Then I thought about using std::bitset and std::vector<bool>.
Perhaps this can be a very popular error,
Code:
#include <stdio.h>
#include <tchar.h>
#include <iostream>
#include <string>
#include <fstream>// enable writing to and reading from files
#include <cstdlib>
#include <time.h>
using namespace std;
class Person {
[Code] .....
Error list:
Code:
Error 1 error LNK2019: unresolved external symbol "void __cdecl saveperson(void)" (?saveperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj
Error 2 error LNK2019: unresolved external symbol "void __cdecl displayperson(void)" (?displayperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj
Error 3 error LNK2019: unresolved external symbol "void __cdecl editperson(void)" (?editperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj
Error 4 error LNK1120: 3 unresolved externals H:Cry_DevProgrammingC++Using_class_ in_ c++DebugUsing_class_ in_ c++.exe 1
What I can do to fit this problem?
Both arrays arr and pointers are the same size. I am having problems reading pointers from file into a new int array.
FILE* ky_pt=fopen("stashedclient","ab");
write(fileno(ky_pt), pointers, sizeof(pointers) );
pointerindex=lseek(fileno(ky_pt), 0, SEEK_CUR );
printf("pointerindex after writing array %d
[Code] .......
Windows 7, 64 bits, Visual Studio 10.
I have a problem to read a large number of binary files, process them and store them under a new name. The program and routines go very well for 505 files. After reading 506 files, the program now refuses to read the next file. I have 16 Gb of memory and tried to close all other programs and restart the PC. it always stops after 506 files (512 files would be more understanding in a way...).
Here is my code. I have tried many things without success. This is only part of the loop that stops. The if test if (myfile.is_open() returns false by some reason. I can start the process again starting with the file that does not open and then it stops again after 506 files.
char * tfiBlock;
ifstream myfile (OrigFilename, ios::in|ios::binary|ios::ate);
if (myfile.is_open()) {
int lengde = myfile.tellg();
tfiBlock = new char [lengde];
//static char memblock [size];
[Code] .....
Clean up procedure:
delete[] tfiBlock;
Are there any limits to how many files that can be opened, or is it maybe someting to be set in the compiler?
I have written in a binary file using fstream an using sort value.
unsigned shortwidth=50,height=50;
file.write((char*)&width,sizeof(width));
file.write((char*)&height,sizeof(height));
When i try to read it back from fstream again there are some symbols (binary obviously). How can i get my values back? I want to read those symbols and in a way to convert them to my old width and height values.
I'm using maps and writing files for the first time and I get a crazy compiler error when I try to compile the following code.
//map is named schedules
// saveSchedule() is a member of the Schedule class that writes a vector of objects to disk, or is supposed to
ofstream newFile("sched.txt");
map<string,Schedule>::iterator in;
[Code] .....
I am trying to use myfile to create and write user data to a file [URL].
At the moment I only want to save as .txt so that I can open it to see that it wrote to file properly.
The main issue I get is that it says the file is not open when my program gets to the error checking at the very end, a few guides mentioned that if the file was not yet created a file with the specified name would be generated in the same folder as main on the hard drive. I did try creating the file as a notepad .txt file but it still read the error. Here is the snippet concerning the writing of the file:
void WriteToFile() {
if(myfile.is_open()) {
myfile.open("userdata.txt",ios::in);
myfile<<"User name: "<<NameFirst<<" "<<NameLast<<"
[Code] ....
it compiles fine with the rest of the program and everything runs smoothly, it just isn't writing to a file.I have included <string>, <iostream> and <fstream>.
So, I was reading that article on binary files:
Disch wrote:
u16 ReadU16(istream& file) {
u16 val;
u8 bytes[2];
file.read( (char*)bytes, 2 ); // read 2 bytes from the file
val = bytes[0] | (bytes[1] << 8); // construct the 16-bit value from those bytes
[Code] .....
u32 would be the same way, but you would break it down and reconstruct it in 4 bytes rather than 2.
But, I don't know what he means by the part in bold text.
I would like to do something like this:
for (int i=0; i<5; i ++)
{
for (int j=0; j<5; j++)
{
//* CREATE A NEW FILE FOR WRITING * //
}
}
I don't know how to create a new file that doesn't get overwritten each time the loop runs.
So lately I've been writing multiple header and cpp files and I would always the same error when I finally #include headers in my main.cpp. This error
Code:
undefined reference to `...`
On Youtube videos I see people doing this and their work magically compiles correctly. I found out that when I #include the headers' cpp files instead, my programs would compile. I use Code::Blocks with GNU GCC compiler.
I a want to write a code to convert a string into binary data for that i wrote a code its working perfectly but there is one problem , some of the binary data is written in 7bit and i want to convert it to 8 bit by adding 0 to the last.
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
[Code]....
So I'm trying to write an array of integers to a binary file. He's my code:
#include <iostream>
#include <fstream>
#include <string>
using namespace std;
[Code].....
I know that it is an array of characters right now, and I will be using the reinterpret_cast when I finish my program. Anyways, when I run the executable, it only writes 1234 to the file. My assumption was that the sizeof() was not being set properly, but even manipulating that won't fix it.
I'm writing a program using Huffman algorithm to compress text file. I have tested my program by just printing the printing ASCII character to file and it worked fine. However, now I have to implement using bits and my program doesn't work. It seems like I'm not reading or writing the right bits. Here is the result of my testing:In the input file I put abc the input file to compress it. Then I uncompress it the out out is aaa. Below is a snippet of how I read and write bits
Code:
class BitInput {
istream& in; // the istream to delegate to
char buf; // the buffer of bits
int nbits; public:
BitInputStream(istream& s) : in(s), buf(0), bufi(8) { }
[Code] ....
I have a text file containing 500 signed decimal numbers. My task is to read each entry and convert into a 16-bit 2's complement representation (binary number) and write into the another text file.
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#include <stdio.h>
struct hardware{
int recNum;
char toolName[30];
int quant;
double cost;
[Code] .....
I'm having issues with my functions working properly. I'm not sure where I'm going wrong with them and if i'm using the correct mode for the fopen.
Is there a way to read and write to the same file?
I'm writing a game program and I want to save the score at the end of the game to a txt file. The txt file already contains other game scores. How do I store the score without overwriting the previous scores.
I'm just using basic fstream.
I have to make a program that asks for your username (any)to register it. When you type it it will say something. I want to create a txt file also. so this is what I have:
#include <iostream>
#include <fstream>
using namespace std;
int main() {
int a;
{
ofstream myfile;
[Code] ....
now, how can I use the cout again to print something "Welcome to the program..."?
I'm writing a program using Huffman algorithm to compress text file. I have tested my program by just printing the printing ASCII character to file and it worked fine. However, now I have to implement using bits and my program doesn't work. It seems like I'm not reading or writing the right bits. Here is the result of my testing:In the input file I put abc the input file to compress it. Then I uncompress it the out out is aaa. Below is a snippet of how I read and write bits
public:
BitInputStream(istream& s) : in(s), buf(0), bufi(8) { }
/** Read the next bit from the bit buffer.
* Return the bit read as the least significant bit of an int.
*/
int readBit(){
int i;
if(nbits == 8){
buf = in.get();
[Code] .....