Thanks again....

I just want to say "Thanks again" to everyone who helped me get past my roadblocks with C++ ... I don't think I'm there yet, but I did manage my first working program today. Couldn't a done it without ya!

Code:

#include <iostream>
#include <algorithm>
#include <vector>
#include <fstream>
#include <string>
#include <windows.h>
#include <shlwapi.h>

using namespace std;

/////////////////////////////////////////////////////////////////////
// Directory listing in a class
//
class DirList
  { private:
      vector <string> Files;
      string Path;
    public:
      DirList();
      DirList(string Folder);
      ~DirList();
      bool GetFiles(string Folder);
      void ListFiles();
      void Sort();
      void Randomize();
      bool SaveList(string Target);
  };

  bool DirList::GetFiles(string Folder)
    { Files.clear();
      Path = Folder;
      Folder += "\\*.*";
      WIN32_FIND_DATA fd;
      HANDLE ff = FindFirstFile(Folder.c_str(),&fd);
      if (ff == INVALID_HANDLE_VALUE)
        return false;
      do
       { if (fd.cFileName[0] != '.')
           Files.push_back(Path + "\\" + fd.cFileName); }
      while ( FindNextFile(ff,&fd) );
      FindClose(ff);
      return true; }

  void DirList::ListFiles(void)
    { for (unsigned int i = 0; i < Files.size(); i++)
       cout << Files[i] << endl; }

  void DirList::Sort(void)
    { sort(Files.begin(),Files.end()); }

  void DirList::Randomize(void)
    { random_shuffle(Files.begin(),Files.end()); }

  bool DirList::SaveList(string Target)
    { ofstream outfile(Target.c_str());
      if (outfile.fail())    // file not open
        return false;
      for (unsigned int i = 0; i < Files.size(); i++)
        outfile << Files[i] << endl;
      outfile.close();
      return true; }

  // structors
  DirList::DirList()
    { cout << "cold init" << endl; }

  DirList::DirList(string Folder)
    { GetFiles(Folder); }

  DirList::~DirList()
    { cout << endl << "Finished!" << endl; }


////////////////////////////////////////////////////////////////////
// Help splash
void ShowHelp(void)
  { cout << "DirToFile -- Save directory lists in files" << endl;
    cout << endl;
    cout << "USAGE :   DirToFile -R <TARGET FILE> <SOURCE FOLDER>" << endl;
    cout << endl;
    cout << "-R Randomize file list (for playlists)" << endl;
    cout << endl;
    cout << "Enclose file and path names with spaces in quotes." << endl;
    cout << endl;
    cout << "Example: DirToFile -r Playlist.m3u \"d:\\My Files\\Music\"" << endl;
    cout << endl << endl;
    exit(0); }


/////////////////////////////////////////////////////////////////////
// Program entry point
//
int main(int argv, char* argc[])
  { // helper splash
    if (argv < 3)
      ShowHelp();

    // parse command line
    bool    Shuffle = false;
    string  Target  = "test.txt";
    string  Folder  = "";

    for (int x = 1; x < argv; x++)
      PathUnquoteSpaces(argc[x]);

    if (!strcmp(argc[1],"-R") || (!strcmp(argc[1],"-r")))
      { Shuffle = true;
        if (argc[2])
          Target = argc[2];
        if (argc[3])
          Folder = argc[3]; }
    else
     {  if(argc[1])
          Target = argc[1];
        if (argc[2])
          Folder = argc[2]; }

    cout << Target << " from " << Folder << endl;

  if (Target.length() < 3)
    ShowHelp();

  if (Folder.length() < 1)
    ShowHelp();

  // sorted or scrambled
  DirList Dir(Folder);
  if (Shuffle)
    Dir.Randomize();
  else
    Dir.Sort();

  // show list on screen
  Dir.ListFiles();
  // write the file
  Dir.SaveList(Target);
  return 0; }

Now the hard part begins....

> int main(int argv, char* argc[])
That's just too confusing!
Almost everyone writes argc and argv

Haha yah that got me too

omg..your first working C++ program and you wrote this...
I need help.

Why do you pass strings by value?
I'd pass them by const reference and even if I needed to change them, I would create a local variable instead.

And when you work with strings, they might throw exceptions (for example std::bad_alloc) and FindClose will never be called. Same with containers.

Good job.

My first C++ program, a couple years ago, was to convert ebcdic data downloaded from a mainframe cobol application into ascii-human-readable data for loading into oracle. I learned a lot.

Originally Posted by Salem

> int main(int argv, char* argc[])
That's just too confusing!
Almost everyone writes argc and argv

LOL... It's been a long time since I worked on console code... but... noted for future!

Originally Posted by Eman

omg..your first working C++ program and you wrote this...
I need help.

Don't panic It's my first C++ but I've been programming in C for a while and Pascal before that so you might say I had a little experience to draw on. You'll get past me... and probably sooner than you think.

Originally Posted by kmdv

Why do you pass strings by value?
I'd pass them by const reference and even if I needed to change them, I would create a local variable instead.

And when you work with strings, they might throw exceptions (for example std::bad_alloc) and FindClose will never be called. Same with containers.

Ok... examples please and thank you...

Originally Posted by Dino

Good job.

My first C++ program, a couple years ago, was to convert ebcdic data downloaded from a mainframe cobol application into ascii-human-readable data for loading into oracle. I learned a lot.

Thank you... and, yes, I am suitably impressed... Havent seen ebcdic coding since I used to repair the old solenoid interfaces for IBM Selectric typewriters...

Originally Posted by kmdv View Post
Why do you pass strings by value?
I'd pass them by const reference and even if I needed to change them, I would create a local variable instead.

And when you work with strings, they might throw exceptions (for example std::bad_alloc) and FindClose will never be called. Same with containers.

Ok... examples please and thank you...

To pass by constant reference change

Code:

bool DirList::GetFiles(string Folder)

to

Code:

bool DirList::GetFiles(const string& Folder)

in both the declaration and definition.

Jim

Originally Posted by jimblumberg

To pass by constant reference change

Code:

bool DirList::GetFiles(string Folder)

to

Code:

bool DirList::GetFiles(const string& Folder)

in both the declaration and definition.

Jim

Thanks... I'll give that a try... (oh the horrible things I'm about to do to this program... )

Originally Posted by kmdv

Why do you pass strings by value?
I'd pass them by const reference and even if I needed to change them, I would create a local variable instead.

But if you're going to change the string, and decide to pass by value, the copy constructor gets called anyway. I'm not sure why people do this, since parameters are local to a function. I can only make sense of this considering a special string class without a copy constructor but a clone() member function. It makes little difference considering it's the STL being discussed.

Passing std::string by reference avoids the call of the copy constructor for the function call.


Jim

Yeah but his post just read "if I were going to change [the strings], I would create a local variable instead," implying that parameters aren't local. Hence, my confused reply.