程序运行，但文件无法打开。 C ++中的命令行

Question

我不确定为什么输入出现的用户提示。我键入“ cat”或“ File.txt”，它将无法打开。我知道我做错了什么，这是我第一次在C ++中使用命令行参数。因此，要么我的代码错误，要么文件不在所需的位置。我将它与.cpp文件放在一起，所以我认为它在正确的位置。 File.txt只是一个txt文件，其中包含3行代码，当用户输入命令时，我需要将其输出到屏幕上。

我还有一个头文件，其中包含一个类以及头文件中所需的所有内容。

class Cat {
public:
  static int main(int argc, std::string argv[]);
};

非常感谢您提供解决此问题的帮助。

//This is Cat.cpp
// Source file for the Cat class
// Implements a command line utility that displays the
// contents of a file.

    #include "Cat.hpp"
    #include<iostream>
    #include<fstream>
    #include<vector>

    using namespace std;

    int Cat::main(int argc, string argv[]) {
        //The main function takes two arguments :

        //1. Check if the user provided the correct number of arguments to the command. 
        //Our version of cat only takes one argument, so argc should be 
        //2. If not, display the message usage : cat <filename> and return 1 (representing failure.)
        //3. Attempt to open the file whose is at argv[1]. 
        //IF the file cannot be opened, display the message error : file not found and return 1.

        //Display the contents of the file.
            if (argc > 1) 
            {
                cout << "File.txt" << argv[1] << endl;
            }
            else 
            {
                cout << ": cat <File.txt>. return 1. \n";
                return -1;
            }
            ifstream infile(argv[1]); //open the file

            if (infile.is_open() && infile.good()) 
            {
                cout << "File is now open!\nContains:\n";
                string line = "";
                while (getline(infile, line))
                {
                    cout << line << '\n';
                }
            }
            else 
            {
                cout << ": File not found. return 1";
            }

            infile.close();

            return 0;
    }

//This is shell.cpp
// This program implements a simple shell

#include <iostream>
#include <string>
#include "Cat.hpp"
#include <vector>
#include <algorithm>

using namespace std;

// Maximum number of arguments (including command) allowed
// in a command line. 
const int MAX_ARGS = 16;

int scanCommandLine(string cmd, string argv[]);

size_t split(const std::string &txt, std::vector<std::string> &strs, char ch)
{
    size_t pos = txt.find(ch);
    size_t initialPos = 0;
    strs.clear();

    while (pos != std::string::npos) {
        strs.push_back(txt.substr(initialPos, pos - initialPos));
        initialPos = pos + 1;

        pos = txt.find(ch, initialPos);
    }

    strs.push_back(txt.substr(initialPos, std::min(pos, txt.size()) - initialPos + 1));

    return strs.size();
}

int main()
{
    //Your shell must repeatedly display a prompt(a $ followed by a space), 
    //then wait for the user to type in a command line.
    //If the user types nothing or only types spaces or tabs, the shell does nothing :

    //The Prompt
    bool exit = false;
    while (!exit)
    {
        cout << "$ " ;
        string cmd;
        cin >> cmd;
        vector <string> args;
        split(cmd, args, ' ');
        //If the user types a valid command, the shell should execute the command and display a new prompt :
        //If the user types exit, the shell exits :
        if (args[0] == "exit")
        {
            exit = true;
        }
        else if (args[0] == "cat")
        {
            string * s = new string[args.size()];
            for (int i = 0; i < args.size(); i++)
            {
                s[i] = args[i];
            }
            Cat::main(args.size(), s);
        }
        //If the user types an invalid command, the shell displays an error :
        else
        {
            cout << args[0] << ": Command not found." << endl;
        }

    }

    //The shell will keep repeating this process until the user types exit.

}

int scanCommandLine(string cmd, string argv[])
{
  int argc = 0;
  size_t start = 0;
  size_t end = 0;
  string arg;

  while(end != string::npos && argc < MAX_ARGS) {
    start = cmd.find_first_not_of( " \t", end );
    if(start == string::npos)
      break;
    end = cmd.find_first_of(" \t", start);
    argv[argc] = cmd.substr(start, end - start);
    argc++;
  }
  return argc;
}