I've spent some time trying to performance test various methods of loading / accessing a file, either into memory or through a memory mapped file, but I am having some trouble.
FILE * pFile; std::ifstream ifs; MapViewOfFile
I'm have trouble because Windows appears to cache the file, so I am getting very mixed results. Sometimes a huge file (100's MB's) will load quickly, other times almost instantly.
How to stop Windows from doing whatever it's doing, so I can see the real time taken to load/access a file from disk?
If let's say I key in 2, it will search for the id=2 and delete the whole line and the id of banana which is orignially 3, will become 2 and orange which is orignally 4 will become 3 etc.
I researched on how it can be done and most suggested to put inside a vector and fout the line.
I know how to put the values in the vector but how should I go about searching for the id and if the id is found it will delete that line inside the file.
Code: ofstream fout; ifstream readFile("fruit.txt"); while (getline(readFile, line)) {
I am suppose to make a program that will output a line for a specific age group,but everytime I execute the exe file it gives me the desired line and also the last line included everytime.Where did I go wrong with it including the last line everytime?
#include <iostream> using namespace std; int main() { double age; cout<<"Enter your age:"; cin>>age; if (0<age && age <6)
Actually the below program is for Dispersal Algorithm called Rabin-IDA; this algorithm divided the data into N pieces and then recombine it from M pieces (such that M<N).
Thus, the below program needs command line arguments,which entering by Project properties/Debugging. this argument is file name, where the program performing spitted the file into N files, and then recombine it from M divided files, and put it on another file which should also passing its name as argument .
Now my question is, How can i make this program enter the file name by keyboard??(i mean enter the files name by user from screen not as command line arguments) ... In another word, How I can exchange ?
Code: argc == 3 and Code: argc == 2
To enter file name ? i mean what i should do to in
Code: rabin.split(argv[1])
To pass my file name by use keyboard not Project properties/Debugging?)
the below code is just the main function of program, and the whole of it in this link [URL] .... Information Dispersal Algorithms Rabin-IDA.
How to get this thing to work. All i need to do is ask user to input a name and then it brings out the line from the .txt file containing the information.
For example in my case I'm doing a member search function I'm required to ask user to input the name of the customer and then print out all the details (which consumes 1 text line in the .txt file)
Here is the code, This is the write to text file method (100% working)
I have a few VC2008 projects whose solutions also includes deployment projects, in which the primary output of several DLLs are included along with the primary apps EXE file. These DLLs are all part of the solution. Now because of the way I do my DLLs, which for lack of better phrase I'll call a true DYNAMIC link (the .LIB file can be discarded), and because I'm careful to ensure full backward compatibility in any new DLL versions, I would like to tell my deployment project to ALWAYS replace existing DLLS with the new versions, or at least offer a choice if it shouldn't be done unconditionally. Unfortunately it never seems to do that!
I'm being careful to create new overall project versions within the deployment project itself, as well as keeping my version resources, attached to each DLL up to date, and always do a full rebuild of everything in the solution (including the DLLs) prior to building the deployment project. But time and again the old DLLs stay un-updated after the install, and the person running it would have no way to know that without examining the target directories and examining file dates and/or versions. A customer shouldn't have to go through all that. I've gotten into the habit of instructing installers to fully un-install old versions before installing a new one, but as you probably know uninstalling from the control panel won't remove shared DLLs.
I was starting to think maybe the latest DLLs weren't being included in the deployment project at all. But if I manually delete those DLLS and do the install, the latest greatest are then always placed.
If I can't find a setting in the deployment project to change this behavior, I'll have to write a separate little console app to force delete (or at least archive) all the relevant DLLs as a pre-installation step. Or maybe supply a BATCH file to do all that, and run the install last. But it seems like a reasonable thing that a setting to make a deployment (MSI) file unconditionally overwrite DLLS, whose version or creation date is newer, ought to be an obvious feature. But if such an option exists, I've missed it completely.
I'm having a bit of problem. I've set the string 'Absent' to all student in a file. However, I want to replace 'Absent' with 'present' when the correct ID assigned to a student is entered. In other words, 'Absent' will only change to 'Present' for a specific person at a time. I'm not sure how to implement this
My text file have 220 663 lines and 858 995 characters (I used Linux commands : wc to count them. If I use array to store data, I think it's too large array. But if use fstream, I dont know to access each element in stream to compare and replace. I dont know How many labels such as: A1, C- A1, AM- MNR... which I have to replace.
To replace a string in my file with another. The file contents look like the following:
abc 123 0
"abc"= The username "123"= Their password "0"= The amount in their bank
I want to change their bank amount.
But, it isn't working, nor is it even giving me an error code.
// When the user logs out, make changes to their bank string strNew = std::to_string(player.bank); // String representation of the revised player bank ifstream filein("user_accounts.txt"); // Old repository of player data ofstream fileout("user_accounts_new"); // New repository of player data
I want to remove some character in my file. too i want to replace some char to another. I know the easiest way for this job is we write final text in file. i mean we first produce sightly text then write it in file . I don't want use of temporary string.
I have a program that gives the user the option to create an employee ID, name, address and so on. It also has the option to search employee by employee ID.
What I want to know is how to add and replace employee info. For example employee changes address. Also how to delete employee information from text file.
Here's my code:
//This program uses file input and output for an employee information system. #include <iostream> #include <string> #include <fstream> using namespace std; int main(){ ifstream inFile; //declare ifstream as inFile and ofstream as outFile ofstream outFile;
I have function which will replace (or create) an file with the contents of another stream. The stream could be anything. The replacement is done safely.
Code: #include <errno.h> #include <stdio.h> #include <stdlib.h> #include <limits.h> #include <unistd.h> int do_replace(const char *file, int stream, int cnt) {
I am trying to read a file line by line and then do something with the informations, so my method looks like this:
Code: void open_file(char *link) { FILE *file = fopen(link, "r"); if (file == NULL) { fprintf(stderr, "Could not open file. "); exit(EXIT_FAILURE);
[Code] ....
1) The first complain of valgrind is at the line where I use fgets and its telling me (invalid write of size x), but I have allocated my line to 56000 and the read line is shorter, why is there a write size error then :S?
2) at the line where I realloc where I try to shrink the space he's telling me: Address .... is 0 bytes inside a block of size 56000, But I know i need only this space so why is there a write over space error :S??
I need to read lines from one file and copy them line by line into another file using dynamic memory allocation. It compiles but gives me a seg fault. Why/How?
I need to read a text file which has various lines containing integers. I need to write those integers separately in a vector. Example, the first line of the text file contains 3 9 8 7 6 so vector[4]=3, vector[3]=9, vector[2]=8 and so on. Next read the second line 4 1 2 3 4 5 and write to another vector vector[5]=4, vector[4]=1...
I tried the code below but it will write from the second line, the whole line in one vector index.
int str; // Temp string to cout << "Read from a file!" << endl; ifstream fin("functions.txt"); // Open it up! string line; // read line count from file; assuming it's the first line getline( fin, line );
As, it can be seen from the above structure that whitespaces are not same everytime. So, to deal with this situation, i am using boost library to remove all whitespaces from the line which is being read and then try to find the name of gate and its input. My code is given below which is able to correctly find the gate names and its first input...but my code is not able to find the second, third and so on input names.
I have to develop a C program that reads a very complex txt file (output of a calculation code, so full of mixed text and numerical tables), search for a specific table in it and individuate/print or replace a specific value with assigned position in the table.
I'm making a binary file that has 100 "empty spaces", and then I want to rewrite specific place with info, however it always writes the info at the end of the file, no matter what I try to get position before I call write() it tells me correct position...
