// OpenFilesCL.cpp
//
// Illustrates use of command-line arguments.
//
#include <iostream>
#include <fstream>
#include <iomanip>
#include <string>

using namespace std;
void InvocationError();
void SplashScreen();

void main(int argc, char* argv[]) {

   // Check for correct number of command-line arguments:
   // 
   if (argc != 2) {
      InvocationError();
      return;
   }

   // Check for help request:
   // (Remember the program name counts as one.)
   if ( (argc == 2) && (strcmp(argv[1], "/?") == 0) ) {
      SplashScreen();
      return;
   }

   char* fileName = argv[1];

   ifstream iFile;

   iFile.open(fileName);
   if (iFile.fail()) {
      cout << "File: " << fileName << " not found in current directory.\n";
      return;
   }

   string Line;

   getline(iFile, Line);
   int LineNumber = 0;

   while (iFile) {

      cout << setw(5) << LineNumber << "  " << Line << endl;

      getline(iFile, Line);
      LineNumber++;
   }

   iFile.close();
}

void SplashScreen() {

   string Splash = "Displays named file to screen with line numbers.\n\n";

   cout << Splash;
   InvocationError();
}

void InvocationError() {

   string Invocation = "Invocation:  OpenFilesCL <file name>\n"
                       "where\n"
                       "      <file name> must be the name of an existing file\n"
                       "                  in the current directory\n\n";

   cout << Invocation;
}