C :: How To Read RAW Sectors From HDD
Nov 27, 2014
I need it to be faster as possible, so poking here and there looks like that a command line utility in C under linux, should do the job fine.I'm aiming at two goals: the first one is to read the raw sector content (means get the 512 bytes of a sector), the second one would be to take this occasion to study the ANSI C language ( I was coding, but too many years ago, quick basic :-) ) and I like to develop in some RAW disk content manipulation analyzing and so on.
For first test I'd like to sequentially read the sectors and print them to screen until a break happen and this would also tuning and benchmarking the whole situation. I'll add a counter to evaluate the average speed (sectors per second)
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Dec 8, 2013
Is possible read text form keyboard using read() function? or which is best way in ansi creplace input command form basic language. for numbers and text...
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May 15, 2013
I want to read the contents of a file block (512 bytes) by block using low I/O read statements. Each record is 64 bytes long and has a pre-defined structure. The first 4 bytes are an unsigned integer; the next 20 bytes are ascii text, etc.
I have a buffer which I can access with buf[0] to buf[63] to read the first record and then buf[64] to buf[127] for the second, etc. However, I was wondering how to map a record so that I can refer to an integer as an integer and a float as float, etc. I can't create a struct and move the 64 bytes to it, as I will have alllignment/padding problems.
What is the standard way to deal with records in C?
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Mar 30, 2013
What is the most efficient way to read a bit at a particular position in a byte?
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Jan 21, 2014
I'm working on a program that reads from a .dat file that has names and numbers associated with the name. What the big picture it will be able to take those names and numbers find the avg of certain peoples scores and display these numbers or names who have the highest etc.
So to keep this short in my main I have it call the class and pass "Even.dat" as a char * fname my questions is how do I go about reading this .dat file? I know sorting it will use a sort algorithm which I will be using a bubble sort. But I haven't worked with ofstream and ifstream very much so some tips would be great! Here's an example of what the .dat file contains
David 42
Rebecca 83
Jonathan 79
Matthew 77
Rose 7
Melanie 75
int main() {
StudentStat StatEven("Even.dat");
[code]....
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Oct 6, 2013
#include "stdafx.h"
#include "iostream"
#include "conio.h"
#include "windows.h"
using namespace std;
void main(){
HDC hdc = GetDC(NULL);
DWORD color = GetPixel(hdc, 500, 500);
[Code] ....
From this code I think it reads pixel from screenshot. I want to read from file. I think I have to change this line
HDC hdc = GetDC(NULL);
but I don't know how to?
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Mar 18, 2015
im trying to make a program which will tell which key i pressed and then it will print in msgbox, but i cant figure out how to read the key in loops, like i tried getasynkey (imported to my c# console app) with value around -32676 or -32767 i ( i found it on internet) and it only shows the key once, i want to do like while my key is pressed, then it will spam my console with key pressed, is there any way to do it?
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Dec 9, 2014
I am a learner in C#. I want to read a particular value from the CSV file. I have learned the getting the csv file into a datatable through browsing. See the following code and my CSV file format. The following code displays all the values.... Say, I want to get what is the 'Volume' for 'ID' = 90.
CSV file (IDVolumeName.csv)
ID:Volume:Name
100:5600:A
95:5000:B
90:4500:C
85:4000:D
Code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.IO;
using System.Data;
[Code] ....
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Apr 22, 2013
I have a code for reading a series of data from a text file.The code was shown below I don't know why I can't successfully read file. (Can open successfully)
btw: the text file and source code were located at the same directory.
#include <stdio.h>
#include <stdlib.h>
int main(){
int numOfAtoms;
[Code]....
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Oct 18, 2014
I read correctly in MatLab some data by serial port of a device, but in C... nothing.
Code: #include <cstdlib>
#include <stdio.h>
int main(void)
{
FILE *in;
char linha[30];
while(1)
{
// Abrir porta COM de onde se ligou a placa
in = fopen( "COM8", "r" );
if( in == NULL )
{
[code].....
The message "ERRO: no consigo abrir porta COM " don't appear, so I haven't error there. I just do not see anything in the terminal.
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Nov 24, 2014
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?
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Nov 24, 2013
When I tried to run my code I keep getting a "Segmentation fault".
I am trying to write a code that read from a file and put the data into a structure.
The file look like the following:
2001,ABBIGAEL,5
1994,ABBIGAIL,5
1996,ABBIGAIL,8
1997,ABBIGAIL,13
The file have 31 lines.
Code:
#include <stdio.h>
#include <string.h>
int main() {
/* Define a daydata structure */
typedef struct {
[Code]....
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Oct 17, 2013
I have a c source file:
Code:
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <regex.h>
typedef struct
[Code] .....
But the problem is i get a seg fault at the read function.
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Mar 3, 2013
How can I erase the data stored in /tmp/a.txt after every run of this code?
Code:
#include <stdio.h> // IO operations
#include <unistd.h> //for pid, ppid, fork functions
#include <sys/types.h> //for pid_t type, kill function
#include <stdlib.h> //for exit function
#include <signal.h> //for kill function
#include <sys/types.h>
#include <sys/stat.h>
[Code]...
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Jul 15, 2013
Ok, I think I got the main idea of the I/O chapter. Though I think I might be oversimplifying the program because I am getting an interesting error.
Goal here is to read numbers from a file and print the numbers with totals for two of the columns and a calculated average for of the totals.
NOTE: The tables for the info from file look a lot better on my end. [QUOTE] seems to mess it up a bit from copying and pasting.
Info from problem:
Car No. Miles Driven Gallons Used
----------------------------------------------------
54 250 19
62 525 38
71 123 6
85 1,322 86
97 235 14
carinfo.txt file:
54 250 19
62 525 38
71 123 6
85 1322 86
97 235 14
program:
Code: updated code
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Nov 26, 2013
Why is this correct?
Code:
char str[10];
scanf("%s",&str);
I knew that when we have strings we should not use & in scanf()...
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Dec 7, 2014
I have learnt recently how to use fgetc, fputc, fputs, fgets but still I am not able to figure out how to read values from a file like for example:
12 14 1928 32993932
17 98
166 109 201
These are separate integers & i want to read them and then manipulate these individual integers like going for 2*I1, 4*I2 and so on where I1 and I2 are 12 & 14.
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Oct 29, 2013
I am trying to read a 24 bit image but I'm getting errors when I'm tryting to read the pixels.
-The reading part looks bad because I'm reading both headers field by field. But I'm sure that it is reading both headers correctly.
-Right now my biggest concern is to get it to read successfully an entire bmp image
I'm using this calculation to get my padding bytes:
padding bytes = [4-(3*width)mod 4]mod 4
When I use a 2x2.bmp file to test it, I get an error that the [1][1] pixel was not read. When I use a bigger image it gives me the same error after about 100 rows and then every pixel is an error from that point on. This is what I got so far:
Code:
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
const size_t cSizeofPixel = 3; //size of struct tPixel
typedef struct{
unsigned char blue;
unsigned char green;
unsigned char red;
[Code]...
I read this post Reading 24 bit BMP file into a 2d array.
I still don't know if my error is when I allocate memory to my 2d array, or if I'm doing the padding bytes wrong or if it is something else.
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Mar 6, 2015
I'm stuck on unix system programming and am beginner about it. Assume that there is a directory which X. There are a file(text1.txt) and another directory which is Y in X. Last, there are two files(text2.noExtension) and text3.noExtension) and another directory which is Z in Y. My goal is that read files and enter directories until there is no directory. How to go on. Example:
Code:
#include <stdio.h>
#include <dirent.h>
int main (int c, char *v[]) {
struct dirent *pDirent;
DIR *pDir;
if (c < 2) {
printf ("Usage: testprog <dirname>");
return 1;
[Code]...
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Mar 13, 2013
I want to be able to read 2 line input, then safe them in separate arrays.
line1 input=array1
line2=array2
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Jan 8, 2014
How can I read contents of a file from the last character? Can I use a loop?
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Nov 14, 2013
I am wondering how can I read a website from a given url in windows ?
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Jan 27, 2014
I have written this program to copy all the characters input from the keyboard into the array till a "?" mark is entered. what is the error i am doing. I am getting a run time error in this case.
Code:
void word_reversal(void) {
char array[100];
int index=0;
printf("Enter the number of characters less than 100
");
do {
scanf("%c",&array[index++]);
}while(array[index] != '?');
}
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Dec 29, 2014
I'm new with C language. I got task to do . Actually there are 2 points. Both should be done with reading text from file. write down all letters from text in reverse alphabetic order (each letter 1 time).write down all words in random order.
I'm stuck with first point. Below code gives me entire text, but i need unique characters only. Text file contains few sentences.
Code:
#include<stdio.h>
void main( ) {
FILE *in;
int ch;
if ( (in = fopen("test.txt", "r") ) != NULL ) {
[Code] ....
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Dec 22, 2013
My program needs to receive data continuously from one process and the received data is read continuously by another process.But when I am trying to create a pipe using mknod on fat32 file system in linux , it throws an error saying "mknod: operation not permitted".
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Nov 19, 2013
How do i read the end of the line in a txt or dat file? I treid using fscanf in a while loop like this
Code:
while(fscanf(pfile,"%c") != EOF && fscanf(pfile,"%c") != '') {
char c = ' ';
fscanf(pfile,"%c",&c);
str += c;
}
The reason why its important to stop after each line is that i need the program to read the data from each line separately.
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