So, it seems I have a bug in my code:
Code:
char *mem = malloc(9), *bottom = malloc(3), *in = "abc";
int position = 2, i;
mem = "onetwo";
printf("OLD mem = %s
", mem);
[Code]....
What I'm trying to do is insert "abc" in the 3rd position of "onetwo". Results would be "oneabctwo", but all I get is crashing.
How can I manipulate a data in a file for example the saved file is like this:
code name Price Quantity
001 hammer 100 4
002 screwdriver 100 4
what i like to do is:
1. the user will be ask to enter its code
2. will output the searched code and then
3. the user will be ask to enter how many pcs he/she will buy.the formula should be
pcs=pcs-users_input if the user selected the code 001 and enters only 1pc it should be updated to only 3 pcs left in the file.
We were given a task to use lists and iterators. We were supposed to make them from scratch. I'm done with that. The problems that I'm having are as following:
1. I'm not able to access the list made of Course datatype which is present in each Student instance. Does this mean I need to make an iterator for that course list inside the student class?
2. Similarly since I don't have direct access to The course list so I added the course into the Student list through the student objects not through the iterator. How can I do it through the iterator?
3. Printing of a particular student and his courses is not happening as my iterator made for student only prints out the students, not the courses present in their courselist. How to do that?
Here's the code
#include <iostream>
#include <string>
using namespace std;
const int ILLEGAL_SIZE = 1;
const int OUT_OF_MEMORY = 2;
const int NO_SPACE = 3;
const int ILLEGAL_INDEX = 4;
[Code] .....
File Data format
A,A
A,B
C,E
C,F
And so on ... it could be up to any alphabet. The number of As and Bs and Cs and Ds in first column depends on the number of unique alphabets used in the first column. For example the unique alphabets used in this case are 2 (A,C) hence each alphabet appears in the first column of consecutive 2 rows.
Which means
Code:
A:A,B,C,D
B:B,C,D,E
C:C,D,E,F
D:D, ,F,G (E is missing)
Actual Data
A,1
A,2
A,3
A,4
C,18
C,33
Final Solution: Add each integer value to its previous value and store the resulting value.
I have the following code and I am trying to do simple math calculations to the data. I need to take the car price (y) minus down payment (z) and then divide that quantity by 12 times "yearsx" That answer is then assigned to x. The problem is that x will not print the correctly!I also noticed that if I increase the "count" to amnything higher than the number on lines in the file, I get the correct value for x but only on the last set of the struct..my file reads as follows:
last_name first_name car_price down_payment years
johnson bill 10,000 2,000 3
When I printf the struct to the screen, i need to do the following:
x = (10,000 - 2,000)/(12*years);
but this is the math part that wont work. I have checked and doubled checked number types and I cant get it right.
Code:
#include<stdio.h>
#include<stdlib.h>
#define FILENAME "file.txt"
#define SIZE 100
}
[code]....
Is it possible to store data to CPU memory, if so how much memory can I store and how? Say I wanted to store an array, about 6MB in size?
View 1 Replies View RelatedWhen I return mem add I cannot access the data in that add: in bin search tree
Curr=findMin(root);
cout<<"val: "<<Curr->barcode<<endl;
bst::hwareItem* bst:: findMin(hwareItem*& root){
while(root!=NULL){
root=root->left;
}
return root;
}
Using the C # programming language LED controller through which controls the array is connected to the controller via the RJ45 port. I already know the basics, I mean specifics, ie
Using the instructions and DLL included with the hardware, I want to read data from it, but I can not deal with it.
Model controller is "C-Power5200" and dll is "CP5200.dll".
I would like to:-pick the data-display-edit and - save in the controller.
To read the data I am using the function
CP5200_Net_Read (BYTE * pBuf, int nSize);
and to save
CP5200_Net_Write (const BYTE * pBuf, int nLength);
I found this elegant looking code on the net that claims to be able to manipulate an images colors using ColorMatrix.
When I run it, it does nothing! I used the code exactly as is with no editing, except to feed it my own image to do its work.
private void ApplySaturation(float saturation) {
float rWeight = 0.3086f;
float gWeight = 0.6094f;
float bWeight = 0.0820f;
float a = (1.0f - saturation) * rWeight + saturation;
[code].....
I am writing a little OS agnostic library for my team for manipulating files.
One such function is used to move/rename files (only files, not dirs). I got into a little argument with a colleague about naming: "rename" or "move"?
"move" makes more sense, but the c api calls it rename.
Is there any historic (or actual) difference between a "rename" and a "move" we could base ourselves on? Or is this purely an Apples vs Oranges?
I have a csv file (comma delimited text file really) and I have data ,about 6400 lines, and I need to read and display data from 1 line. At the bottom is sample data from my csv file.
I want to read onto the screen the 3rd item .. ie Test User 1 and the date and time at the end (the last 2 items).
I will enter in a number .. from which I will want to retrieve the appropriate record .. in this case I would enter in 514, 563 or 874 and get back the info for that record.
This is a DOS 16 bit application .. and I know that some of the data is in memory already but I am not sure how to tell .. or how to retrieve it.
I do have the ability to save the data to the file at any time .. so I can use that to ensure that the data is current in the text file before I retrieve the data from this 1 row.
I think that it may just be easier to get from the text file ? but I am not sure.
0000,7,0,"Test User 1",53c145cb,db,5,514,514,2014/07/12,10:27:23
0001,7,0,"Test User 2",53d7f,1903,10,563,563,2014/07/24,11:04:31
0002,7,0,"Test User 3",529c,5ffb03,0,874,874,2013/12/02,09:07:58
I am a database guy .. and I am just a bit lost when it comes to C programming as such.
So, if I'm right, computer store their data as binary values. So if I write int x = 5; , my computer converts the value of x from decimal (5) into binary (101) and stores it in memory as a a binary number. If I print that value on the screen that value is converted(by default) back into a decimal number before being printed on the screen.
Now, my question is if there is any way to print the value of x directly into binary(as it's stored in memory) without it being converted back into a decimal value?
I have a data buffer project in Windows 7 x64 embedded OS (using Visual Studio 2008), that would work simply like that:
One writer application will send data (no network protocols, just procedure call on the same machine) to my app like 20 packages per second, each data packages will be approximately 3 MB size and comes with a timestamp tag.
My application will store each data item for 100 minutes and then remove. (So I can calculate the total size from beginnig no need for dynamic allocation etc...)
Meanwhile there will be up to 5 reader applications which will query data from my app via Timestamp tag and retreive data (no updates or deletitions on data by reader apps).
So since the data in my buffer app can grow over 50GB I don't think that shared memory is going to work for my case.
I'm thinking about using Boost Memory Mapped Files or Windows API Memory Mapped Files.
So theoratically I will crate a fixed size File on harddisk (lets say 50GB) and then map some portion to RAM write the data to this portion, if the reader applications wants to use the data which is mapped currently on memory, then they will use directly, otherwise they will map some other potion of the file to their address spaces and use from there...
My problem is I haven't use Map File concept at all and I'm not a C++ developer so I'm not very familiar with the language fundementals. I've searched tutorials of boost and msdn for windows as well but there is not too much code example.
So I don't know how to map some portion of the data to memory and manage it, also how to search data in file or memory according to the timestamp tag. Yes there are codes for creating files and mapping the whole file to memory but none for dividing it into regions, aligning or padding the data which I need for my case.
I serialize a XML file, and i have this values here:
public class ServiceConfig {
public List<DatabaseDescriptor> Databases { get; set; }
} public class DatabaseDescriptor {
[XmlElement("Name")]
[Code] ....
I have a form1 which is a datagrid view and get's updated like this:
dataGridView1.DataSource = xmlData.Databases;
Now i have a button: get tables, and it opens up form 2, there it's supposed to appear all the tables of the selected Database, when i click on the row i get the database name so i get all the list of Tables from
DatabaseDescriptor
where
DatabaseDescriptor.Name == name
(I get this when i select the row)
But then on the 2nd form, i also have 2 textbox so i add a new table, i add the tablename and id. the new value should appear in the datagridview of the tables, and when i close it and reopen it, it should be there. Maybe i should concatenate first the values or something, how do i do?
Implementing and manipulating a Polynomial ADT using a linked list.
So far I have:
poly_ADT.h
Code: typedef struct nodeT{
int coef;
int powr;
struct nodeT *next;
} node;
[Code]...
I need to create a function that creates the polynomial using input first.
poly *poly_create (num,...) ;return a new polynomial with num terms terms are listed in order of lowest ordered-term to highest. i.e., to initialize poly 15x^6 + -9x^4 + 3x^2 call poly_create(3, 3,2, -9,4, 15,6 );
Once I do that I need to implement various functions that can manipulate the polynomial itself but I'm having trouble just with creating the polynomial itself, how to do that using a linked list and nodes?
I need manipulating a set of containers. I created a vector that contained vectors of objects:
std::vector< std::vector<Terrain> > mapArray(num1, std::vector<Terrain>(num2));
where num1 and num2 are arbitrary numbers. and Terrain is the class of objects I'm trying to store.
I want to be able to use push_back on both the main vector and the vectors within the mapArray vector but I'm unsure of how to target the inner vectors with push_back. How to dynamically store a 2D array of objects.
I have an assignment that wants me to better understand how certain calls like malloc() and free() work. I'm supposed to have one function that allocates a pool of memory for the program to use (this is the only place where I'm allowed to use the malloc function. Anyplace else is off limits, except when allocating space for data structures.) Another function needs to be defined that allocates memory from this large pool of memory that we have already allocated. A third function needs to free a block of memory when a call from function main is made and a fourth does something else (haven't gotten that far yet.) I'm not sure if it's ok or not, but I'll attach the pdf form that describes all the requirements. If that's not ok, I'll delete it.)
Anyways, when thinking of data structures to use for this particular problem, one doesn't jump out at me as being THE data structure that would be most useful. How I would imagine using it is to store the addresses currently being used as well as the block length of those addresses (so basically, each node of the linkedlist would have a pointer that points to an allocated address and another field that told the size of the allocated block of memory.) How to communicate to the large pool of memory that a certain block of memory has been allocated and shouldn't be used until a free is made on that specific block of memory.
Attached File(s)
pa3.pdf (61.07K)
When you have constant arrays, they are stored in the programme memory space. Upon execution, they are copied into the data space for easy access. To save space in the data space, it is possible to stop it from being copied. Some compilers will deal with this by just specifying the array as const, g++ has a type modifier called PROGMEM.
In any case, the problem is that I'd like to generate some data, preferably without using an external programme to do it. Hence, my question using the template system. Now I could possibly use macro metaprogramming via boost instead of template metaprogramming, and I may have to go that route. However there are limitations, especially since its numbering system is only equivalent to an unsigned byte, which I possibly could use, but could become more messy than if I use the template system that has long long types as well as a whole slue of type safety mechanisms.
I am doing a project which I have to read, write and erase data from a NorFlash Memory. Then, I have to compare those data files in order to find errors.
Besides, I would like to know which is the best way to TEST errors in this kind of memories.
I am using NetBeans 7.3.1 for writting the code and Cygwin running on Windows XP Virtual Machine. The Memory Flash (S29JL064J 64 Megabit) is incorporated on an external board which is connected to an adapter board (using HDMI cable). This adapter is connected to the Laptop (using an USB).
Why do most C examples pass a double pointer when manipulating linkedlists? Why can not we just pass a single pointer to the struct?I think using an external reference accessor for a linked list would be a more appropriate solution, yes or no?
View 1 Replies View RelatedI have a program that stores health information the user inputs, one person at a time. The program works perfectly with the exception of storing the data...I need to open a file and read what health data it has in it already, if any, but store the new changes, and appended data to the array of structures, to the data in memory. All of the information is only saved back in the file once the program terminates. I'm not sure how to go about doing this, so I am also not sure what to put in the function for "Save and Exit" that the user can choose in order to exit the program.
Code:
#include "stdio.h"
#include "stdlib.h"
#include "string.h"
struct strdatabase
{
char first[20];
char last[20];
char gender[2];
[Code]...
I tried playing around with this bit of code, but I'm not sure if I'm even on the right track.
Code:
FILE *fp;
fp = fopen ("students.txt","rb"); fseek(fp, 0, SEEK_END);
long pos = ftell(fp);
fseek(fp, 0, SEEK_SET);
char *bytes = malloc(pos);
fread(bytes, pos, 1, fp);
fclose(fp);
I am trying to write a client/server application that takes input to an array of structures from the user,stores the data in a shared memory segment and then writes the same to a file when I close the application. How do I get started? And how do I ensure that the server stores the data correctly? Also, the server needs to be a concurrent server that accepts connections from multiple clients.
View 1 Replies View RelatedI got an assignment at school asking for a program that can implement functions that store, get and deletes text/binary data to a given memory area. We are supposed to make kind of like a tiny-mini OS..any links to some tutorials or explanations hon ow to understand this and be able to make a program like this on my own?
View 9 Replies View RelatedI need to find inverse of a matrix data in binary file should be used to form matrix.its not finding inverse correctly rest is working good.
Code:
#include <stdio.h>
void createbin();
void display();
void inverse();
int main()
{
createbin();
display();
inverse();
[Code] ....
I am writing a program where I need to read a byte of char data and convert it into a text string of binary data that represents the hex value...
i.e. The char byte is 0x42 so I need a string that has 01000010 in it. I've written the following subroutine....
------------- My Subroutine ----------------------------------------------------------------------
void charbytetostring(char input, char *output){
int i, remainder;
char BASE=0x2;
int DIGITS=8;
char digitsArray[3] = "01";
[Code] ....
When I submitted the byte 0x42 to the subroutine, the subroutine returned to the output variable 01000010... Life is good.
The next byte that came in was 0x91. When I submit this to the subroutine I get garbage out.
I am using a debugger and stepped through the subroutine a line at a time. When I feed it 0x42 I get what I expect for all variables at all points in the execution.
When I submit 0x91 When the line remainder = input % BASE; gets executed the remainder variable gets set to 0xFFFF (I expected 1). Also, when the next line gets executed..
input = input / BASE; I get C9 where I expected to get 48.
My question is, are there data limits on what can be used with the mod (%) operator? Or am I doing something more fundamentally incorrect?
I have written the following code to add data to text files which are required to store 3D scan data (I have to calculate the y-coordinate). My code seems to work except that it stops working when I want to create more than ten text files i.e. the directory I am trying to store them in will not hold any more than ten text files. Code is shown below.
#include <string>
#include <locale>
#include <iomanip>
#include <iostream>
#include <fstream>
#include <sstream>
using namespace std;
[Code] ....
