C++ :: How To Forbid File Replacing In Fstream Library
Jul 25, 2013How to forbid file replacing in fstream library for C++?
#include <iostream>
#include <fstream>
using namespace std;
int main() {
ofstream myfile;
[Code] ....
ADVERTISEMENT
C# :: Writing To A File (Not Replacing)
Dec 11, 2011I have a question about an issue I am having on my final project. Within my ItemEntry.cs form, I am trying to get the application to append the already existing .txt file, rather than prompt the user to replace it. I can't seem to get the StreamWriter and FileStream to allow the user to write to the file.
Code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
[Code] .....
C :: Implementing Recursive Merge Sort - Forbid Warning
Jul 8, 2013I am trying to implement a recursive merge sort, and I've just barely begun. I am getting some warnings:
merge_sort.c:15: warning: ISO C90 forbids variable-size array 'left'
merge_sort.c:15: warning: ISO C90 forbids mixed declarations and code
Code:
#include <stdio.h>
#include <string.h>
static void
merge_sort(int *a, int n)
[Code] ....
I am using gcc 4.2.1 and I am compiling with -Wall and -pedantic.
C/C++ :: Reading A File And Replacing Characters With Corresponding String
Mar 27, 2014So I am supposed to create a program that reads a file and replaces "<" with "<" , ">" with ">" , "&" with "&" , and " " " with """.........
The program takes a file "test.txt" and reads it, replaces the characters above with the corresponding strings, and then writes the output to "scrubbed.txt".
A sample input would be: <something>
and the output would be: <something>
for some reason I am getting garbage In my new file. What am I doing wrong with the code?
#include<stdlib.h>
#include<stdio.h>
#include<ctype.h>
#include<string.h>
int main(int argc, char **argv){
char *inFileName = NULL;
char *outFileName = NULL;
FILE *instream = fopen("test.txt", "r");
FILE *outstream = fopen("scrubbed.txt", "w");
[Code] ....
C++ :: Reading From TXT File / Replacing Word And Then Overwriting
Nov 21, 2014My goal is to open a .txt file and replace words in it then overwrite it. My goal is half way done. It couts it perfectly, but I am having a hard time overwriting the whole text file exactly how it couts it. I want the text to be exactly how it is displayed. In this example, I want to replace "ABC" with "DEF".
Text file "A.txt":
1 2 ABC 4 5
6 ABC 8
#include<iostream>
#include<string>
#include<fstream>
using namespace std;
int main() {
string Y;
fstream IN("A.txt", ios::in | ios::out);
[Code] ......
C++ :: Create File With Fstream?
Feb 18, 2014For some unknown reason when i try the following code it doesn't create a file. (the program will simply get two inputs from the user and then use http to obtain the html/php text and then output it to a file)
code:
#include <SFML/Network.hpp>
#include <iostream>
using std::cout;
[Code].....
C++ :: How To Use A User Entered File In Fstream
Feb 14, 2014So, I am making a name-database-type-thing and I want the user to be able to enter there own file. Like, here:
string fileName;
string name;
cout<<"What is your file name?"<<endl;
getline(cin, fileName);
ifstream nameFile(fileName);
getline(cin, name);
nameFile<<"Name: "<<endl;
Well, that last part is in a loop, so you can enter an unlimited number of names to the .txt file.
So, it won't let me use the string in ifstream. How can I fix this? This maybe unclear, so if it is just say so and I will edit it.
C++ :: Reading And Writing To File Using Same Fstream
Oct 16, 2013I have a file of data where each line consists of 4 parameters (degree, alpha, beta and x) and a value corresponding to these, organized in increasing order of the parameters. Here's the test file I'm using:
0 1 1 0.5 3.5
1 1 1 -0.5 -0.5
1 2 0 0.2 4.5
1 3 0 0.2 -4.5
2 0 0 1.5 2.1
2 1 0 0 5.6
My code is supposed to look for a certain set of parameters (currently set to 1 2 1 1.5, which is not contained in the file) and its value. If it's there (i.e. the file contains the value for the right parameters) the program is done. If not it should calculate the value using a function JacobiPoly() and insert the wanted parameters and corresponding value in the appropriate place in the file.
I have a code in which I think everything works except the writing to file. I use an fstream so I can both read and write and open it with ios::out||ios::in. I'm also aware I need something similar to fseek in between input and output but according to [URL] .... reading and writing to the same file using the same fstream, seekp() should suffice. I'm using seekp(), but the output (in the form inout << (...)) doesn't work.
Here's the code:
fstream inout;
inout.open("inouttest.dat", ios::out | ios::in);
int degree=1, readDeg;
double alpha=2, beta=1, x=1.5, value, readAlpha, readBeta, readX, readVal;
bool foundVal=false;
streampos beforeRead=(streampos)0;
[Code] ....
C++ :: Fstream - Writing In The Middle Of A File
Sep 7, 2012I want to edit the contents of a file using fstream, but none of the modes in the fstream constructor work for me.
If I use ios::trunc, then the whole file is deleted - but I want to retain the contents and edit it. If I use ios::app, then I can only add data to the end of the file - but I want to edit the data in the middle of the file. If I use ios::ate, then the whole file is deleted again, similar to ios::trunc.
How can I create an fstream object without deleting the contents of the file, whilst still being able to move the pointer arbitrarily around in the file with seekp() (and not just placing it at the end as with ios::app)?
C++ :: Link Between (STL) Container And (Fstream) File I/O?
Nov 9, 2012I did some of the projects using STL container and it is pretty much efficient to retrieve the data's information quickly (i.e. sets, sets & maps). I read many C++ OOP book and none of them make me clear about the Link Between (STL) Container and (Fstream) File I/O. Can they link together ?
I am going to design a small Library Book Management Project. I am planning to develop it using the STL Algorithms & containers. Objective of this project is to keeping the records of books issued and deposited by students in a particular date. User will be given a facility to retrieve student's information, book information and he/she can modify/update specific book's, student's information by changing issue date, deposited date, Book's publication etc.
My intention is to create a File I/O where user can input & update/modify daily transaction inside the file called (xx.dat) file in project directory. Is it possible to create 'set' container inside the file (xx.dat) ? Or, It's impossible ? Or, do i have to do this in other way?
C++ :: How To Delete A Line From Text File Using Fstream
Dec 16, 2014I'm trying to make a simple phonebook app that can show contacts, add, and delete. I'm pretty new to C++ and fstream functions, deleting a line in my bool erase() function?
#include <iostream>
#include <conio.h>
#include <string>
[Code].....
Visual C++ :: Crashing On Fstream Open File
Jan 20, 2013other posts talk about the fopen function and don't really give any solutions to this the var that has the file path is a char* and has been converted from a system::string^ it is completely valid when I paste it in windows bar.
Code:
private: System::Void button3_Click(System::Object^ sender, System::EventArgs^ e) {
if(textBox1->Text[0] == (char)'' || textBox2->Text[0] == (char)''){
MessageBox::Show("Please select a valid m3u and path", "Problem",
MessageBoxButtons::OK, MessageBoxIcon::Exclamation);
[Code]....
it crashes right at the pile.open() function call when I put breakpoints in it says , debug assertion failed and shows me the fclose.c file location and Expression: (stream != NULL)
C++ :: Writing Text Data To A Binary File With Fstream
Jul 9, 2014fstream ifs;
ifs.open ("data.str", ios::binary | ios:ut);
char *data1 = "data1";
char *data2 = "data2";
ifs.write(data1, strlen(data1));
ifs.write(data2, strlen(data2));
when i this,data2 is not going under data1, i thought each write starts on a new line?
C/C++ :: How To Write Class Objects To Text File Using Fstream
Jan 15, 2014I need to a simple example for writing class' objects to a text file using fstream , I tried to search the forums and I found binary examples but not for to a text file.
View 8 Replies View RelatedVisual C++ :: Using Fstream To Open A File Created Only During Runtime?
Nov 20, 2012I'm using Visual C++ 6.0 and I'm trying to use fstream to open and read a file that is created only during runtime. This file is written by another function running on another thread, and my program will keep trying to "open" the file until it can be opened, i.e. after it's created, then read 3 numbers from it and execute the rest of its code.
The file test.txt has the content
Code:
1
3
4
My program that polls and opens the file is as follows:
Code:
ifstream fin;
std::string tfile, snum1, snum2, snum3;
long int num2, num3;
tfile.assign(argv[1]);
printf("Begin prog %s
", tfile.c_str());
[code]....
I executed the program by
Code: test_prog.exe "C: est.txt"
and waited about 3 seconds before putting the test.txt file into C:
My output was
Code:
Begin prog C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
fin is open
snum1 =
num2 = 0 num3 = 0
End of prog
The test.txt file disappears after I refresh the C: folder.
So the values for snum1, num2 and num3 are all wrong, as if the file was not read correctly.
If I put a while fin.good() loop after printf("fin is open "); for that entire block (until printing the values of num2 and num3), then I get
Code:
Begin prog C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
Cannot open file C: est.txt
fin is open
End of prog
How can I correctly read a file that is only created during runtime?
Visual C++ :: Copying One Bmp File To Another Using Fstream - Access Violation Reading Location
Dec 31, 2014I would like to copy one bmp file to another using plain fstream (none 3-rd party library). I've managed to come up with something but I keep getting error:
Unhandled exception at 0x504A3442 (msvcr120d.dll) in ConsoleApplication1.exe: 0xC0000005: Access violation reading location 0x00380000.
when i try to write the content of the bmp files not the header, namely error occurs in this line:
Code : ofs_differential.write((char*)&picture, (bfh_warm.bfSize - bfh_warm.bfOffBits));
Also i am not sure if i am doing it in a right way, meaning that even after solving this error i will copy the bmp file successfully.
Code:
// ConsoleApplication1.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include <iostream>
#include <fstream>
using namespace std;
struct BITMAPfileHEADER {
unsigned short bfType;
[code]....
C++ :: Read And Write Multiple Class Objects From File - Fstream Won't Work Correctly
Apr 28, 2014So I have a small program which is supposed to write and read multiple objects from a file, but for some reason it doesn't write the information when I use "fstream" to create the object from the fstream class, but it does when I use "ofstream". Also, it doesn't read the information from the file no matter if I use "fstream" or "ifstream". I watched a video where this exact code worked just fine, but it just won't work when I run it. I'm using Dev C++ 4.9.9.2, I don't know if that has anything to do with it, I also tried it with Code::Blocks, didn't work either.
Here's the code.
#include <iostream>
#include <fstream>
using namespace std;
class Person
[Code].....
C/C++ :: What Library To Use To Read BMP File
Jul 25, 2014I need to write a program that will read a .bmp image file of an 8 by 8 pixels resolution and write the data about every pixel in a text file. The problem is, that I can't find a library to use. I've tried using CImg but even the basic test examples fail with "undefined reference to setdibbitstodevice...." or something like that. I know CImg is a powerful library and it can even manipulate images, but I need something just to read it.
View 2 Replies View RelatedC++ :: Linking Static Library To CPP File
Jun 20, 2013I have a libcx3d.a which contains my VrmlParser class and other classes which are used by VrmlParser. I have a main.cpp which does this :
VrmlParser vp = new VrmlParser();
double **VOB = vp.getVOB();
When I compile using g++ main.cpp -o main -L. -lcx3d, I get the following errors :
'VrmlParser' was not declared in this scope.
expected ';' before vp.
'vp' was not declared in this scope.
There is a header file called "VrmlParser.h" in the static library. Should I include this header file in main.cpp ? If so, will include "VrmlParser.h" work ? I have the .a and .cpp in the same directory. I can't find the header file for the static library.
C++ :: Thread Library - No Such File Or Directory
Jul 25, 2014When I write a code in c++ includes thread library it says "thread:no such file or directory". How can ı use thread library .
I think I should download boost or c++11 but I couldn't do it .
C++ :: How To Parse XML File With Standard Library
Mar 11, 2015How can I parse an .xml file with just C++ Standard Library?
View 14 Replies View RelatedC++ :: Replacing Strings In A Vector
May 22, 2014Alright I hav a program that readings from a txt file but is there a way to replace some of the words that get loaded into the vector so for example if the txt has a list of animals and i want to replace the word bird for book is their a way to do that
#include <iostream>
#include <string>
#include <vector>
#include <fstream>
[Code]....
C++ :: Replacing Macro With Constant
Apr 4, 2013I heard that const shall be preferred over #define . So I start to change my program accordingly.
But then below error message occurs during compilation:
#include "common.h"
#include "definition.h"
#include "particle.h"
int main() {
Particle *p = new Particle();
[Code] .....
I guess the error occurs because, when the line 9 of particle.h (File 4) is compiled, value of const int dimension is not seen by the compiler.
C/C++ :: Replacing Letters In A Word?
Aug 13, 2014i'm trying to replace letters in a word...here's the code so far
#include <algorithm>
#include <iostream>
#include <string>
using namespace std;
int main (){
string s;
[Code] ...
The problem is if i type "nm" i'm not getting "mn" as the output, it's "mm"
I'm not trying to swap letters between them
C :: Create Polymorphic Linked List Library File?
Sep 10, 2013Linked lists seem to be the most erroneous and most frequent thing I use and post about nowadays. I've been wanting to handle data structures in my own library of functions, but I'm not sure how to imitate polymorphism without too many ambiguities. I could just pass some character or string value to represent a type, but I wanted to see if there was actually something more elegant I could use before I dive in.
View 4 Replies View RelatedC++ :: Find Non Printable ASCII Value - Using Library File Unittest
Jan 3, 2014My program is find non printable ASCII value(1 to 32) and calculate count from a text like "hi<tab>this<space>my text.i'm using library file here.(visual studio 2012)
removeascii.h(program name)
#pragma once
#include<stdint.h>
#include <string>
using std::string;
namespace ascii
[Code] ....
My ERROR is:
1>c:program files (x86)microsoft visual studio 11.0vcunittestincludecppunittestassert.h(65): error C2338: Test writer must define specialization of ToString<const Q& q> for your class class std::basic_string<wchar_t,struct std::char_traits<wchar_t>,class std::allocator<wchar_t> >
[Code] ....