Reading multiple files one by one - c++

Question

I am almost done with my project, but I still have one small thing that needs to be done...I need to run the entire program for each file in the directory. There are about 200 files in total. Below is the main class of the program that needs to run. I'm thinking I will put the entire thing in a do-while loop and run it until there are no more .dat files in the directory, but I'm not sure if that will work. Obviously, I'd like to replace the hard-coded file names with variables...I'm just not sure how to do that, either. Please let me know if you need clarification. I've been working on this project for a while and I'm getting kind of brain-numb. Thanks in advance for your help!
Edit My test directory is on a Windows machine, but it will be uploaded to a linux machine at school.
int main() {
NearestNeighbor face;
//string path = "C:\Users\Documents\NetBeansProjects\CSCE350";
//string searchPattern = "*dat";
// string fullSearchPath = path + searchPattern;
/*TEMPLATE DATA*/
/***********************************************************************************/
fstream templateData;
double data = 0.0;
templateData.open("003_template.dat", std::ios::in);
//check that the file is opened
if (!templateData.is_open()) {
std::cerr << "Template: Nooooooo!\n";
exit(0);
}
/*************************************************************************************/
//fill the templateVector with the values from templateData
std::vector<std::vector<double> > templateVector;
std::string line;
while (getline(templateData, line, '\n'))
templateVector.push_back(face.splitData(line));
//testing the contents of the templateVector
// cout << "TemplateVector: ";
// for (unsigned i = 0u; i != templateVector.size(); ++i) {
//
// std::cout << "Index[" << i << "] ";
// for(double value : templateVector[i])
// std::cout << value << " ";
// std::cout << "\n";
// }
/*QUERY DATA*/
/************************************************************************************/
std::ifstream inFile("003_AU01_query.dat", std::ios::in);
std::vector<double> queryVector;
double pixel = 0.0;
// Check that the file opened
if (!inFile.is_open()) {
std::cerr << "Query: Nooooooo!\n";
exit(1);
}
// fill the queryVector with the query data
while (inFile >> pixel) {
queryVector.push_back(pixel);
}
inFile.close();
// testing the content of the query vector
// for (unsigned i =0u; i < pixels.size(); i++){
// std::cout << "Index["<< i << "] " << pixels[i];
// }
// std::cout << "\n";
/*OUTPUT SCALAR PRODUCT*/
/****************************************************************************************/
vector<double> theList;
/*break out each of the vectors from the templateVector and compute the scalar product*/
for (auto& vec : templateVector) {
int i;
cout << "\nscalar_product: Index[" << i << "] " << face.scalar_product(vec, queryVector);
theList.push_back(face.scalar_product(vec, queryVector));//fill theList vector with the computations
i++;
std::cout << "\n";
}
//make sure that the sorted products are output with their original index numbers
vector<pair<int, double> > sorted;
sorted.reserve(theList.size());
for(size_t i = 0.00; i != theList.size(); i++){
sorted.push_back(make_pair(theList[i], i));
}
//sort the scalar products and print out the 10 closest neighbors
face.quickSort(sorted);
cout << "\nVector after sort:\n";
for(size_t i = 0; i < 10; i++){
cout << "idx: " << sorted[i].second << " " << "val: " << sorted[i].first << endl;
}
}

Answer 1

A solution in bash:
#!/bin/bash
for file in `ls`
do
./program $file
done
Of course you'd have to modify your main function to take an argument to pass to the fstream constructor:
int main(int argc, char **argv)
{
if (argc != 2)
{
// some error handling code
}
ifstream templateData(argv[1]);
if (!templateData)
{
// more error handling
}
// process the file
}

Answer 2

From your code it is windows.
This code will print all the *.dat file names in your folder:
Instead of printing do whatever you like.
first You'll need to include:
#include <windows.h>
Now to the code:
const wstring dir = L"C:\\Users\\Documents\\NetBeansProjects\\CSCE350";
const wstring ext = L"dat";
wstring findstr = dir;
findstr += L"\\*.";
findstr += ext;
WIN32_FIND_DATA ffd;
HANDLE hFind = FindFirstFile(findstr.c_str(),&ffd);
do{
if(!(ffd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)){
wstring path = dir;
path += L"\\";
path += ffd.cFileName;
wcout<< path<<endl;
}
} while (FindNextFile(hFind, &ffd) != 0);
FindClose(hFind);
EDIT:
On linux you can give your program a parameter path/to/dir/*.dat and you'll get the parameters trough argv, maybe its the better solution.
But if you insist to do it with code it is like this:
includes:
#include <sys/types.h>
#include <dirent.h>
Now the code:
const string dirname = "path/to/dir";
const string ext = ".dat";
DIR *dir;
struct dirent *de;
if((dir = opendir(dirname.c_str())) == NULL) {
//error... check errno and so on
cerr<<"Error..."<<endl;
}else{
while ((de = readdir(dir)) != NULL) {
//you can use stat to check if is is file or dir...
string filename(de->d_name);
if(ext = filename.substr(filename.size()-ext.size())){
cout<<dirname<<"/"<<filename<<endl;
}
}
closedir(dp);
}
Good luck