We typically don't bother with massive, monolithic code files that get processed from top to bottom. In the Object Oriented world, code files don't mean much. In fact, in C#, I could have multiple classes defined in one file, or have one class split across several files.
View 7 RepliesI am writing a piece of code that requires me to display the last 1000 lines from a multiple text files (log files). FYI, I am running on Linux and using g++.
I have a log file from which - if it contains more than 1000 lines, I need to display the last 1000 lines. However, the log file could get rotated. So, in case where the current log file contains less than 1000 lines, I have to go to older log file and display the remaining. For e.g., if log got rotated and new log file contains 20 lines, I have to display the 980 lines from old log file + 20 from current log files.
What is the best way to do this? Even an outline algorithm will work.
I'm using multiple C++ files in one project for the first time. Both have need to include a protected (#ifndef) header file. However, when I do that, I get a multiple definition error.
From what I found from research, adding the word inline before the function fixes the error. Is this the right way to do this, and why does it work? Should I make a habbit of just declaring any function that might be used in two .cpp files as inline?
Here's a few parts of a program I'm working at. It does compile, and it does work as expected. Anyway Eclipse Kepler marks one line as a bug with the remark Field 'befehl' could not be resolved. The bug sign didn't show up when both classes were in one file.
ScriptInterpreter maintains and processes a vector of Objects, initialised with example data. An iterator of the vector keeps track of the current position while various methods process the data. I've copied the relevant lines only.
I can live with a few wrongly bug-marked lines in Eclipse. What I don't want is any hidden errors that express at some time later.
Is there anything wrong with the code? Anything that's not recommended and compiles anyway? Is anything c++11-specific about the questionable line?
AtomicCommand.h
class AtomicCommand {
public:
int befehl;
[Code] .....
Note that line 9 has a bug sign, too. Eclipse doesn't recognise all my c++11 code.
I am writing a bit-check function just to make it easier on myself to check status flags in my classes. I use char variables and each bit represents something on or off. Since I have numerous classes that will use this functionality, it makes sense to write and compile the code only one time rather than for each class. I was thinking of writing the function and including it as a "friend" function to each class that needs it. Is that an appropriate way to do it?
View 2 Replies View RelatedI am having the issue of trying to call functions of a class through the header file.
Test.h
#ifndef TEST_H
#define TEST_H
class Test {
public:
void Hello();
[code]....
This code returns the error "undefined reference to 'Test::Hello()'"
All I am trying to do is call the Hello(); function in a seperate file.
I have heard that people should implement their class member functions in files that are different from their class declaration files. But in cases there are multiple classes that are inter-related to each other, how will you review the source code ?
View 1 Replies View RelatedI am struggling to enable friendship between two classes in separate header files for a banking program.
I am attempting to get the Person class to use variables from the Account class. Heres what I have so far.
ACCOUNT.h:
Code:
#include<iostream>
#include<fstream>
#include<cctype>
#include<iomanip>
#include <string>
#include <math.h>
#include <windows.h>
#include <vector>
#include "Person.h"
using namespace std;
class person;
[code].....
I'm trying to print a single linked list backward with functions/classes. I have created the main file and 3 header files. But I'm getting an error on one of the header files, linkedListIterator after adding #include "linkedListType.h". It says that "linkedLlistType.h" is calling itself. And when I try to run it, I get an error of "too many header files." I have tried changing the headers many times, but nothing seems to work.
.cpp file:
/*(Printing a single linked list backward) Include the functions reversePrint and recursiveReversePrint, as discussed in this chapter, in the class linkedListType. Also, write a program function to print a (single) linked list backward. (Use either the class unorderedLinkedList or the class orderedLinkedList to test your function.)*/
#include "linkedListType.h"
#include "orderedLinkedList.h"
#include "linkedListIterator.h"
#include <iostream>
using namespace std;
struct nodeType
[Code] ....
header files:
[URL] .... (error in this header file)
[URL] ....
So I have a rather large (for me) project, requiring me to have two .cpp files and a header. Anyway, both of the .cpp files #include the header file, but I recieve linker errors because the variables and functions in the header are declared and defined twice (once in each .cpp file). How am I supposed to do this?
View 8 Replies View RelatedI am struggling with the concept of having different ccp's and header files. I made a really bad example project for representation, but basically my question is are any of the #includes unnecessary that I have? Technically it functions, but if I am doing it wrong I want to prevent myself from starting bad habits in the future. My code just basically uses strings and sets a name and prints it. My code is really bad, but I wanted to just use includes in such a way for a quick example.
//MAIN.CCP
#include "functions.h"
using namespace std;
int main()
[Code]......
I am trying to run multiple source files but right after the first one finishes running the program closes and doesn't move on ...
View 2 Replies View RelatedHow I can compile multiple source file in visual studio 2012 ???
View 1 Replies View RelatedI was trying out programs based on extern and as i understand, this is useful when accessing variables across multiple files having only one definition. But i tried a simple program as below without "extern" and thing seem to work when i expected it would fail during linking process
Code:
file5.c
1 #include <stdio.h>
2 #include "var.h"
3
4 int main() {
5
6 printf("
File5.c a = %d", a);
[Code] .....
As i have included "var.h" in all header files without extern, "int a" would be included in both the .c file and during linking, compiler should have thrown a warning or error message but it compiles file without any issue. Shouldn't var.h have the following "extern int a"?
I have a big un-editable program, A, which I need to run for like a 1000 different input files. It takes about 15 minutes for each file, so a little parallelisation wouldn't hurt.
I have installed openmpi and it works fine. I have made a small program, B, which selects an input file, moves it to another directory, calls program A with the path to the selected input file and then - when A is done - selects a new input file etc. It should loop until there are no more files in the initial directory.
The problem is this: When I have several processors they might pick the same file and that leads to errors. I have a working program, but it is not pretty.
Code:
#include <stdio.h>
#include <mpi.h>
#include <dirent.h>
#include <string.h>
#include <stdlib.h>
int main(int argc, char *argv[]) {
int num_procs, procs_id, i, exit;
struct dirent *ent;
[Code]...
Every time a processor tries to move a file that another processor has just moved, the output shows an error message before looping to the next file and trying again. It works, but it is a bit annoying. So my questions are:
1) Can I switch off the error message somehow?
2) Is there a better way to do this?
So say I create a header file which contains a list of structs, and I want to use these structs through out my source and some of my classes... how would I accomplish this?
When I try to do it via #include, I get re-definition errors, due to the nature of #pragma once. If I switch to #ifndef then I lack defenitions in files other than the source.
Is there a way to define things such as structs across multiple files, which doesn't lead to re-definition errors, and doesn't involve manually re-created all the structs for each file?
I am currently working on a C++ program for school. I am actually not finding too much difficulty in constructing the functions, enum-types, arrays and structs, however, I am finding great difficulty in using on ifstream variable to open multiple files.
I have posted the entire code that I have so far (even though I have pinpointed the issue to not properly opening the second file in ifstream).
I spent a couple of hours getting rid of certain functions/procedures, loops and variables and I get the same output (if what I removed doesnt crash it). I also get the same output whether I "open" the second file or not (meaning I removed all of the code for it and got the same output).
Here is the code (it's not finished because I am stuck on this file issue). It's a bit messy since I am now in debug mode versus program mode:
I have been working on code for quite some time and am able to successfully read in a text document and take certain words and information that I need. The issue is that I need to read in close to 100 plus documents and was wondering how I could read in the multiple documents. I thought about creating a structure of arrays and have each text document be an element and walk through taking each document but I am not sure how this works.
View 8 Replies View RelatedI am trying to get variables that are global to multiple files. I have mananged to make constant variables that are global but maybe not in the best way. In the header i have the constant variables being defined:
const int variable_Name = 5;
And the cpp file:
#include <iostream>
using namespace std;
#include "vars.h"
int main ( ) {
cout << variable_Name<< endl;
system ("pause");
return 0;
}
Is there a better way to do this and to make the variables able to be changed within the cpp files.
I am trying to create n number of files (n being an integer), by passing the name through a character array (and obviously changing its value at each iteration). But the problem is that the program compiles and executes but not a single file is created.
Here is my code snippet.
void file_phipsi(int m)
{
int a=0,n=0;
char *str1;
[Code].....
I am new to c++ programming i just want to know how to write the data into different files.Suppose my input files has 1-8 ids so each id data must be stored into each different file. And below is my code.
#include<fstream>
#include<iostream>
#include <cstdlib>
#include <algorithm>
#include<list>
#include <math.h>
#include<conio.h>
#include<string>
#define PI 3.14159265
using namespace std;
double angle;
ifstream indata;
ofstream outfile;
[Code] .....
I want to create a namespace named MyNS.
Can I define it in multiple files?
I mean:
file1.h
namespace MyNS {
const int File1 = 0;
} file2.h
namespace MyNS {
const int File2 = 1;
[Code] .....
I have attached my code below and I am stuck in what to do next to make an instance of the dateCls so I can use the instance to assign the open date. By instance I mean like create an instance of the class, like this: dateCls myFirstInstance; And everything in the dateCls I can access through the . operator. So far my code looks like this..what I should do? Lastly, I am using derived data from I think the bankAccountCls.
I need the main program to output this data:
dateCls openDate(01, 03, 2012, "open date");
saveAccountCls s1("1001", 300.50, 0.12);
s1.setDate(openDate);
s1.print();
s1.deposit(100, 01, 05, 2012);
s1.print();
s1.withdraw(50, 01, 10, 2012);
[code]....
I have two files that I want to compile:
main.cpp
Code:
#include <iostream>
using namespace std;
int ReadNumber();
void WriteAnswer();
[Code] .....
The compiler complains:
io.cpp||In function 'int ReadNumber()':|
io.cpp|3|error: 'cin' was not declared in this scope|
io.cpp||In function 'void WriteAnswer()':|
io.cpp|7|error: 'cout' was not declared in this scope|
io.cpp|7|error: 'endl' was not declared in this scope|
In io.cpp file, should I put the two statements ("include <iostream>" and "using namespace std") at the top, outside of the functions?
Or should I put the two statements inside each of the functions?
I am working on one application that requires extensive logging so I want to create a log file of each day during execution.
I tried easylogging++ but i am unable to use into multiple files. If i try to use in other file. I get compilation errors of using same functions or methods already defined.
How can i use macro to hide the implementation of logging in one class to other ??
I have managed to make a program that permutates a string with repetition.
I ran it to permutate "abcdefghijklmnopqrstuvwxyz1234567890" with a limit of 5 characters.
This took a little over 5 hours for my pc to process this and I ended up with a .txt 403MB in size. Needless to say I am unable to open this .txt in notepad without Notepad.exe not responding and me having to end the process.
So what I want to do is modify my code to break up the output in to several files rather than one. Possibly all permutations starting with a in one file, b in another, etc.
Here is my current code:
#include <iostream>
#include <string>
#include <sstream>
[Code]....
As you can see it currently appends permutation.txt with all output. I would like it to make files like this permut_5char_a.txt, permut_5char_b.txt, etc.