Den stora tråden för snabba nybörjarfrågor

#include <iostream>
#include <fstream>

int main(){
    std::ifstream dataFile;
    dataFile.open("../data/test.txt");
    if (dataFile.is_open()){
        std::string line{""};
        while (std::getline(dataFile,line)){
            std::cout << line << "\n";
        }
        dataFile.close();
    }
    else {
        std::cout << "Unable to open file...\n";
    }
    return 0;
}

#include <iostream>
#include <fstream>

int main(int numArgs, char *args[]){
    std::string aux(args[0]);
    int pos = aux.rfind('/');
    std::string path = aux.substr(0,pos+1)
    std::string dataPath{""};
    dataPath = path + "../data/test.txt";
    std::ifstream dataFile;
    dataFile.open(dataPath);
    if (dataFile.is_open()){
        std::string line{""};
        while (std::getline(dataFile,line)){
            std::cout << line << "\n";
        }
        dataFile.close();
    }
    else {
        std::cout << "Unable to open file...\n";
    }
    return 0;
}

#include <iostream>
#include <fstream>
#ifdef TEST_DATA_PATH
    std::string dataPath;
#endif

int main(){
    std::ifstream dataFile;
    dataFile.open(dataPath);
    if (dataFile.is_open()){
        std::string line{""};
        while (std::getline(dataFile,line)){
            std::cout << line << "\n";
        }
        dataFile.close();
    }
    else {
        std::cout << "Unable to open file...\n";
    }
    return 0;
}

CXX = g++

COMPILER_FLAGS = -Wall -s -DTEST_DATA_PATH=/path/to/test/data/test.txt

LINKER_FLAGS =

OUTPUTNAME = test

SRC = ./src
INC = ./include
BIN = ./bin
OBJ = ./obj

MAIN = $(SRC)/main.cpp

ALLOBJECTS = $(OBJ)/*.o

main : $(MAIN)
	$(CXX) $(COMPILER_FLAGS) -c $(MAIN) && mv *.o $(OBJ)

test : $(OBJ)
	$(CXX) $(OBJ)/*.o $(LINKER_FLAGS) -o $(BIN)/$(OUTPUTNAME)

all :
	$(CXX) $(SRC)/*.cpp $(COMPILER_FLAGS) $(LINKER_FLAGS) -o $(BIN)/$(OUTPUTNAME)

clean :
	rm -rf $(BIN)/$(OUTPUTNAME) $(OBJ)/*.o

/path/to/test
total 36
drwxrwxr-x. 8 erik erik 4096 Sep 23 19:23 .
drwxrwxr-x. 3 erik erik 4096 Sep 23 18:54 ..
drwxrwxr-x. 2 erik erik 4096 Sep 23 19:22 bin
drwxrwxr-x. 2 erik erik 4096 Sep 23 18:54 data
drwxrwxr-x. 2 erik erik 4096 Sep 23 18:54 include
-rw-rw-r--. 1 erik erik  499 Sep 23 19:23 makefile
drwxrwxr-x. 2 erik erik 4096 Sep 23 18:54 obj
drwxrwxr-x. 2 erik erik 4096 Sep 23 19:24 src
drwxrwxr-x. 2 erik erik 4096 Sep 23 18:54 test

#include <iostream>
#include <fstream>
#include "../include/read_conf_file.h"
#include "../include/read_data_file.h"
#ifdef HELLO_CONF_PATH
std::string defaultConfig = HELLO_CONF_PATH;
#endif

int main(int argc, char* argv[]){
    std::string dataPath;
    if (argc == 1){
        dataPath = readConfFile(defaultConfig);
    }
    else if (argc == 2){
        dataPath = readConfFile(argv[1]);
    }    
    else if (argc > 2){
        std::cerr << "Unsupported behaviour. Use 0 or 1 argument.\n";
    }
    if (argc <= 2){
        readDataFile(dataPath);
    }    
    return 0;
}

#include <iostream>

int main(){
    std::string userInput;
    int x{0};
    int y{0};
    bool myLoop{true};
    while (myLoop){
        if (userInput != "exit"){
            std::cout << "Enter x: ";
            std::cin >> userInput;
            if (userInput != "exit"){
                x = std::stoi(userInput);
                std::cout << "Enter y: ";
                std::cin >> userInput;
                if (userInput != "exit"){
                    y = std::stoi(userInput);
                    std::cout << x << " + " << y << " = " << x + y << "\n";
                }
            }
        }
        else if (userInput == "exit"){
            myLoop = false;
        }
    }
}

#include <iostream>
#include "../include/get_value.h"
#include "../include/print_result.h"

int main(){
    std::string userInput;
    int x{0};
    int y{0};
    bool myLoop{true};
    while (myLoop){
        std::cout << "Enter x: ";
        x = getValue(userInput);
        if (userInput != "exit"){
            std::cout << "Enter y: ";
            y = getValue(userInput);
        }
        if (userInput != "exit"){
            printResult(x, y);
        }
        if (userInput == "exit"){
            myLoop = false;
        }
    }
    return 0;
}

#include <iostream>
#include "../include/get_value.h"

int getValue(std::string &userInput){
    int value{0};
    std::cin >> userInput;
    if (userInput != "exit"){
        try {
            value = std::stoi(userInput);
        }
        catch(...){
            std::cout << "Invalid input! Input = " << value << "\n";
        }
    }
    return value;
}

#include <iostream>
#include "../include/print_result.h"
#include "../include/my_division.h"

void printResult(const int x, const int y){
    std::cout << x << " + " << y << " = " << x + y << "\n";
    std::cout << x << " - " << y << " = " << x - y << "\n";
    std::cout << x << " * " << y << " = " << x * y << "\n";
    myDivision(x, y);
}

#include <iostream>
#include <quadmath.h>
#include "../include/my_division.h"

void myDivision(const int x, const int y){
    if ((y != 0) && (x % y != 0)){
        __float128 z{0};
        z = (__float128)x / (__float128)y;
        char buffer[128];
        quadmath_snprintf(buffer, sizeof buffer, "%.32Qf", z);
        std::cout << x << " / " << y << " = " << buffer << "\n";

    }
    else if (y != 0){
        std::cout << x << " / " << y << " = " << x / y << "\n";
    }
    else if (y == 0){
        std::cout << "Divide by 0 error...\n";
    }
    return;
}