C++ :: How To Read Struct From Binary File
Oct 12, 2014I have this file want to read it source code [URL] ....
View 10 RepliesI have this file want to read it source code [URL] ....
View 10 RepliesI have a file in which I have written a structure called "Record".
Here is the struct definition:
#define IDSIZE 10
struct Record{
char id[IDSIZE];
int score;
};
[Code]....
Your goal is to open this struct of students (the binary file). Once open, the first job is to print out each student. Afterwards, display all students with a gpa of 3.5 and higher. Finally, display all students with the major of Computer Science or Game Programming. Be sure to title each category of items.
He gave us a .cpp file and a .h file that we're suppose to use to run the program. He doesn't want us to change his original code, except we can add the needed code to run his code (i.e. Struct & Main).
My problem is that I get an Abort() crash message in VS2013 when I try to run it. Now, in line 95 of the cpp file if I replace the char* with "", it runs fine showing the GPA with blank entries for the other print parameters. I've read the Binary Files chapter of the Pearson textbook several times and it doesn't have anything to say about working with char pointers.
Header file:
#pragma once //Professor's code
struct StudInfo //Start of my code {
char* fName;
char* lName;
char* major;
double gpa;
[Code] ....
im trying to write an array of struct to a binary the array of struct is filled with data from a text file .
the program gives no errors or warnings but does not write anything at all to the binary file here is the main
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
struct matches
{
char teamA[20] ;
char teamB[20];
int scoreA ;
int scoreB;
[Code]....
I have a structure :
struct Entrainement{
string muscleCible, nom, unitesObjectif;
double objectifActuel, dernierObjectif, objectifInitial, capaciteInitiale, progression[10];
};
and I want to write in a binary file the structure. The following works perfectly....
(*pointeurFichierEntrainementBin).write((char*)&exercice, sizeof(Entrainement));
except when the string exceed 11 characters. I guess it's because it has to pick a fixed sized for the string? but what if I want to always be able to have string up to 200 character? because now I can't exceed 11..I know writing a string with c_str() works, but I would like to write/read the structure in one shot.
Below is the code for reading a struct that was stored in a binary file. Problem is while reading from file I get the name without first character and age is always equal to zero which it should not be.
#include <iostream>
#include <conio.h>
#include <fstream>
struct abc {
char name[100];
int age;
[Code] .....
I have a file in which I have written a structure called "Record".
Here is the struct definition:
Code:
#define IDSIZE 10
struct Record{
char id[IDSIZE];
int score;
};
Here's the code where I wrote to the file:
Code:
Record record;
char* id = "H12345678";
int score = 50;
record.id = id;
record.score = score;
file.write((const char*)&record, sizeof(record));
}
Here's a screenshot of the file in windows: [URL].... To the left is the id, 9 characters. To the right, well I'm assuming that's the score that I wrote.
And here's the problem, reading from the binary file:
Code:
Record record;
fstream file(argv[1], ios::in | ios::binary);
if(!file){
cerr << "Could not open the file." << endl;
return 1;
}
char* id = new char[IDSIZE];
[Code]...
The ID reads perfectly. The score...always returns 0, despite that it should show "50".
I am having a structure called matrix as shown below to represent a matrix your read from a text file.
struct matrix
{
double mat[30][30]; //content of the matrix mat
int row; //number of row in the matrix mat
int col; ////number of col in the matrix mat
};
Declare 3 variables of structure matrix, m1, m2 and m3 in main to be used as describe below.
Task:
1.Write a function void readFile(char *filename, matrix *m) that will read a matrix from a text file and copy to the structure matrix m.
How to save the struct to file and then read it back from the file ?
Code:
#include <conio.h>
#include <stdio.h>
struct student {
int person;
int egn;
float AvergeGrade;
[Code] ....
Have average grade: %f", person[i].FirstName, person[i].LastName, person[i].egn, person[i].AvergeGrade);
}
//Save to file
getch ();
}
I am trying to use struct to store variables from a text file and use them in the main program. I have first tried running the program without using struct and declaring the variables within the main program and it runs fine. But after using struct, it gives no compilation error and a segmentation fault as output. Also, if the size of file/variable size is unknown can I declare variables as char string[]??
The code is as below:
Code:
#include<stdio.h>
struct test {
char string1[10000];
[Code].....
This is a c++ Code. I want to read a address to a pointer. When I try to do so it generates an error. I did is >> obj1[0].contentAdress; in main.
struct node3{
node3(){
nextContent = NULL;
for (int i = 0; i<1020; i++)
content[i] = '';
[code]...
no operator found which takes a right-hand operand of type 'node3 *' (or there is no acceptable conversion)
I am parsing a binary data file by casting a buffer to a struct. It seems to work really well apart from this one double which is always being accessed two bytes off, despite being in the correct place.
Code:
typedef struct InvoiceRow {
uint INVOICE_NUMBER;
...
double GROSS;
...
char VAT_NUMBER[31];
} InvoiceRow;
If I attempt to print GROSS using printf("%f", row->GROSS) I get 0.0000. However, if I change the type of GROSS to char[8] and then use the following code, I am presented with the correct number...
Code:
typedef struct example {
double d;
}
example;
example *blah = (example*)row->GROSS;
printf("%f", blah->d);
When reading a binary .img why is it when you read it by slurping in the file, then save it to a string and cout, you don't see the binary but random garbage?
View 11 Replies View RelatedI am trying to get the code to read from the txt file one bite at a time and then write this bite into the binary file but i cant seem to get it working.
FILE *fpcust, *fpcustbin; //<<<<<-----point to both sales and customers text files, and the new .bin files for both
char buffer;
int ch;
int ch1;
fpcust = fopen("c:customers.txt", "r"); //<<<<-----pointing to the file
fpcustbin = fopen("c:customers.bin", "wb"); //<<<<<-----pointing to the new binary file, opening in writing binary
[Code]...
I use the following function to read doubles from a binary file:
Code:
int64_t read_current(FILE *input, double *current, uint64_t position, uint64_t length)
{
printf("asked for %" PRIu64" samples
",length);
printf("reading from %" PRIu64 " to %" PRIu64 "
",position,position+length);
union{
double d;
uint64_t i;
}
[code]...
As long as position+length doesn't exceed the end of the file, all is well. However, if it does, weird things start to happen. In particular, the apparent length of the file (that is, the value of "read" after the function has finished) becomes dependent on "length"). I know that "position" is never past the end of the file.
I'm trying to do file compression/decompression in C and I need to handle one bit at a time.
I currently try to do:
unsigned char byte = fgetc(fptr);
and later
byte >>= 1;
but the problem is that I have to use the first bit of the byte and then treat the next 8 bits as one byte. The byte usage keeps shifting over in this way. It's probably quite clear that I'm a bit lost.
Trying to write very simple code to read a 4 byte int from a file.
code:
int tester;
FILE *fp;
fp=fopen("/home/bdluser/skeleton.blx","rb");
fread(&tester,sizeof(int),1,fp);
printf("tested 1 byte read should be 1: %i",tester);
I have tried editing the binary file....it outputs similar large numbers
00000000000000000000000000000001 outputs 808464432
0x00000001 outputs 808482864
0x10000000 outputs 808548400
10000000000000000000000000000000 outputs 808464433