Code:
char buffer1[10];
char buffer2[10] = "something";
sprintf(buffer1, "with %s", buffer2);
In a statement like the one above, is there a threat/leak or does it only truncate the string that is loaded into buffer1?
preventing a buffer overflow when dealing with strings being passed as arguments.
If I have a function prototype such as:
Code:
void foobar(char *bar);
That argument bar - is intended to take a pointer to a buffer of x characters in length. Inside that function, I can't get the size of that buffer, as bar is now just a pointer to a char. I COULD just make the user of this function pass a length parameter, but there is no guarantee that would be correct. Is there a bullet proof way of detecting that the user has provided a buffer that is too small?
I'm using a uC to read the device ID from a One Wire device. I'm trying to have the ID read every second and output to over a USART serial stream for debugging, however I'm having a number of problems getting this to work correctly and I think it has to do with my misunderstanding of memory allocation in this case.
The problem is that when I upload the binary to the uC, it gets the device ID correctly the first time, and from thereafter the program is unstable and starts returning garbage (1st screenshot).
Ideally everything inside of the while loop would be inside of its own function, however I have had nothing but trouble doing that. In fact, when I put that all into it's own function that returns void and takes BUSES as an input, the correct data comes out the first and therefore it somehow exits the "while" loop and never gets back in (2nd screenshot). Another thing I noticed is that when I put the variable declaration outside of the while loop in the code below, I get the same behavior.
I haven't include the code for OWI_DetectPresence and OWI_SendByte ... I've hooked up an oscilloscope and have visually confirmed they are working correctly. Once the OWI_ROM_READ byte is sent over the bus the slave responds with it's device ID. I feel like my issue here is memory allocation and not hardware.
how to fix the issue with the output to USART and how to make this into a function that returns the string of the hex ID?
Code:
int main(void) {
unsigned char OWI_on_bus = FALSE;
// initialize UART for debugging
Init_USART();
[Code].....
I am trying to add a small function to allow me to pause the game I am making. I measure the time elapsed using the following algorithm:
1. USE ""clock_t begin=clock();"" FOR SYSTEM TIME OF GAME BEGINNING.
2. USE ""cout<<(clock()-begin)/CLOCKS_PER_SEC;"" TO DISPLAY TIME ELAPSED IN SECONDS.
Now, if I want to pause, I would want to subtract the 'paused' time from the total time elapsed.Say,
clock_t pause, resume;
{
pause=clock();
.
.
.
resume=clock();
}
Then I would do cout<<(clock()-begin-(resume-pause))/CLOCKS_PER_SEC;
This, though is what I want, works only once(I can pause only once). I can use arrays of resume and pause, but it would still limit the number of times I can pause.
What I am looking for is a way to pause any number of times.
Suppose my file a.txt has "ABC" written in it. Now I want to write a small b before capital B in the file. How will I do it. I've tried to do it but i'm having problems.
1. When opened in app mode seekp doesn't work.
2. When opened normally previous written data is erased.
I am trying to find the best way to detect a small symbol such as :
Just for testing features I tried to load these into SURF example that comes with EMGU and it does not pick it up... And I think the technology used for SURF is better for objects with more details and color gradients...
I was just wondering how to deal with overflow. My code works for exponential when i put small numbers in like 2 and 3. So it would do 2^3 which would be 8. But if i try something like 2^44 then I just get 0.
View 2 Replies View RelatedI am having difficulty with arrays because of the limitation of the size of the arrays that I can declare. I need sizes that are very large and windows or C# does not allow me to create bigger than the following for example:
public static int[] gaPoints = new int[20000000000000000000 + 1];
I get an error message saying that "integral size is too large".
I need to be able to declare sizes that are even much larger than the abovementioned size.
How can I circumvent this problem?
Do I have to use something other than arrays?
I want to store a very small number - too small for even a long double. However, I don't need the number to be stored very precisely - in fact, all I really need is the order of magnitude of the number. For example, the number 5.205849034425 X 10^-381 can just be stored as an integer of -381 for my purposes. I don't really care about the precision of the 5.205849034425 part.
The reason I get this very small number, is because I am multiplying together thousands of numbers, all of which are around 0.0001 in value. So, one way to do this would be to store all these individual values as simply their order of magnitude (e.g. -4) and then instead of multiplying the numbers, I would just add up their orders of magnitude. However, I am wondering whether there is a way in C++ to do this without me having to change the way I store my data - I still would like to keep the original values if possible.
I'm getting a stack overflow error because for large numbers, this code I'm working on allocates too much on the stack.
Is there a way of tracking stack allocations specifically?
Will multithreading solve my problem if each thread is doing the static allocations?
Would I really have to use malloc or new every time I wanted to use memory just to make my code scale to huge numbers?
I usually check if a bit is set using:
Code: bit = (number >> n) & 1; where `n` is the bit I want to check...
But I came across a stackoverflow answer saying:
bit = number & (1 << x); will not put the value of bit x into bit unless bit has type _Bool (<stdbool.h>).
Otherwise, bit = !!(number & (1 << x)); will..
So why is this? why the double !?
Here is my error message: Warning1warning C4717: 'getx' : recursive on all control paths, function will cause runtime stack overflow
and here is my code I will Bold the part that is giving me problems!
class point
{
public:
point();
[Code]....
Whenever I try to call merge sort on large numbers say n=10000000. It gives an error. It works fine for small numbers, even though I have declared my Lists on the heap.
The below code is just the divde part.
List<long>* Merge(List<long> *ParentList) {
if((ParentList)->Length==1) {
return ParentList;
[Code] .....
Im trying to do a small program that will create multiples of the previous line *2, and spit out the anwser in seperate lines (as many times as the user wants)
Example if i wrote it in a bad way
2
4
8
16
32
etc.
At this time my code looks likes this, now im planing to get my hands on the IF statment
using System;
using System.Collections.Generic;
using System.Linq;
[Code].....
Small code to show overflow...But when I compile and run - buffer_one is not being overwritten when the byte size of buffer_two overflows .
Code:
#include <stdio.h>#include <string.h>
int main(int argc, char *argv[]) {
int value = 5;
char buffer_one[8], buffer_two[8];
strcpy(buffer_two, "two"); //Put "one" into buffer_one
strcpy(buffer_one, "one"); //Put "two" into buffer_two
}
[code]....
I am performing arithmetic operations on very large integers that operate around the threshold of the maximum positive integer an int variable can handle (i.e. 2147483647) for a 32-bit machine. I have been studying the in-built functions in the C++ Standard Library for some time now where I came across some error detecting functions in the <cmath> and <cerrno> header files. The impression I got from the literature is that they are solely used in conjunction with functions contained in the <cmath> header file and not necessarily with fundamental arithmetic operations like addition and subtraction.
I need a means to know when my arithmetic operations generate overflows/underflows! Is there any way I can adapt the functionalities of these functions to my needs?
After not programming for sometimes I decided to program a small application. But I have some trouble according to what I remember and re-checking arrays online. I don't understand how the code I wrote below is possible, shouldn't give a stack overflow error or something to that extent? Instead it gives me the value of 3.
#include "stdafx.h"
#include<iostream>
int _tmain(int argc, _TCHAR* argv[]) {
int arr2 [2];
arr2 [3] = 3;
[Code] ....
I've finished my series of tutorials and built a investment calculator with QT, now that's finished and I wanted to create a small radio that allows to retrieve audio from an URL. I wanted to use Juce but I'm clueless about it, I know how to program but I've never touched external libraries?
View 2 Replies View RelatedI have been writing a program to generate pairs of RSA keys using small prime numbers. I have been using mpz_invert() to get a value for d for the private key. On small prime numbers it calculates the correct value, but on larger primes it calculates incorrect values.
I'm assuming there must be an upper limit to the values the mpz_invert() function can handle? If so, what is this limit to avoid erroneous values?
I'm pretty new to C, and keep getting an error. Basically I'm trying to convert a ppm image to all red. Here is my code that I can't get to work:
Code:
change(pixel_t *PIXEL, &w, &h,pixel_t *buffer);
And here is the beginning of my convert function:
Code:
void change(pixel_t *pixel, int w, int h, pixel_t *buffer) {
int average, sum;
int i;
pixel_t *pointer;
Everything else works fine. I keep getting an error when I call the convert function. It says "expected expression before pixel_t" and "too few arguments to function "change". I know that everything else in the main is working.
Why the size of a process grows larger in size for lots of small memory allocations. For example, say I have this struct, which is 16 bytes (for a 32 bit build):
Code:
struct Person {
int iID;
int iAge;
char * pForeName;
char * pSurName;
};
If I allocate memory like this:
Code:
LPBYTE lpB = new BYTE[sizeof(Person) * 1000000];
Then my process grows to 16,48KB in size, which is what I expected. However if I allocate memory like this:
Code:
Person * lpPerson;
for(int i = 0; i < 1000000; ++i)
lpPerson = new Person;
Then the process grows to 78,656KB, which I don't understand.
Additionally, I was surprised to find a vector acts more similarly to the first example. This code:
Code:
Person temp = { 0 };
std::vector<Person> people;
for(int i = 0; i < 1000000; ++i)
people.push_back(temp);
Only increases the process memory to 16,892.
I am trying to implement the insert function of a binary tree. Atm when I try and insert 3 nodes, the program breaks and gives me a stack overflow error. The error points to a getter function for an identifier for the data in my node class.
void LinkedList::add(Product *myProduct) {
if (_length==0) {
_head = new Node(NULL, NULL, myProduct);
_end = _head;
_length=1;
[Code] ....
Here is my insert function, the error message is
"An unhandled exception of type 'System.NullReferenceException' occurred in SDI2.exe
Additional information: Object reference not set to an instance of an object. "
In my main I have declared an instance of product, "productToAdd = new Product(id,idPrice);" so I'm a bit confused as to what I need to include..
Why I have a
HTML Code:
FLOATING POINT ERROR: OVERFLOW
ABNORMAL PROGRAM TERMINATION
in the code below?
Code:
#include<stdio.h>
#include <math.h>
#include<conio.h>
#define A 0
#define B 1
float F(float x0, float y0) {
return (0.2*x0)+(y0*y0);
[Code] .....
What is wrong with this code? I keep getting
HTML Code:
FLOATING POINT ERROR: OVERFLOW
ABNORMAL PROGRAM TERMINATION
Code:
#include<stdio.h>
#include<math.h>
#include<conio.h>
#include<iostream.h>
#define N 4
float x[5]={0, 1, 2, 3, 4};
float y[5]={0.5, 2, 7.5, 20, 42.5};
[Code] ....
I have an int array of size 5 and I have my program to accept 5 integers between 10 and 100 inclusively. I should be able to type integers over and over again until I get 5 that are in the range, 10 <= x <= 100. Now when I get 5 that fall in that range the program should continue but instead it wants a 6th number before continuing. I'm suspecting the program is hanging on to a new line character. Anyway to ignore the new lines? Couldn't find anything for C# without clearing the screen.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DupElim {
//dup elimination
[code]....
Im creating a permissions profiler in c by using stat()I ran into a problem of getting a bad address as in my path. Ive tried multiple solutions with no dice, and now I have one more solution I want to try but I dont understand how.how do you use a snprintf and pass that into a buffer, and pass that into a path for stat()?
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