用用户输入打开不同目录下的文件

C++ Opening files in different directories with user input

本文关键字：文件 用户 输入      更新时间：2023-10-16

我一直在编写一个c++程序，它将最终从文本文件中删除某些不需要的格式。遗憾的是，我离这个目标还有很长的路要走。

我目前的问题是我似乎无法打开位于给定(用户输入)目录中的文本文件。这是我到目前为止所做的，剥离了最不需要的块:

//header, main function, bulk
//variable definitions
FILE * pFile;
//char filePathBuffer [512];  --unused, from older attempts
string currentLine = "", command = "", commandList = "ct", filePath = "defaultPath";
int quotePos = 0, slashPos = 0, bufferLength = 0;
bool contQuote = true, contSlash = true;
cout << "> ";
getline(cin, command);
//various exit commands
while(command != "q" && command != "quit" && command != "exit") {
    //check for valid commands stored in a string
    //--definitely not the best way to do it, but it's functional
    if(commandList.find(command) == commandList.npos) {
        puts("nPlease enter a valid command.n");
    }
    else if(command == "t") {
        puts("nPlease enter the file path:n");
        cout << "> ";
        getline(cin, filePath);
        //rip all quotes out of the entered file path
        while(contQuote == true) {
            quotePos = filePath.find(""");
            if(quotePos == filePath.npos)
                contQuote = false;
            else
                filePath.erase(quotePos, 1);
        }
        pFile = fopen(filePath.c_str(), "r+");
        //I've also tried doing countless variations directly in the code,
        //as opposed to using user-input. No luck.
        //pFile = fopen("C:\test.txt", "r+");
        if(pFile!=NULL) {
            cout << "nFile opened!" << endl << endl;
            fclose (pFile);
        }
        else
            cerr << "nFile failed to open!nn";
    }
    //reset variables to default values
    quotePos = -1;
    slashPos = -1;
    contQuote = true;
    contSlash = true;
    cout << "> ";
    getline(cin, command);
}

我实际上不确定输入字符串是否应该有引号-我无法让它们以任何方式工作。我还尝试执行filePath.find('')来查找反斜杠(这样我就可以在filePath中添加第二个反斜杠以进行正确的解析)，但最终没有成功。

你们知道我该如何补救这种情况吗?

谢谢!

我建议您在调用fopen时查看filePath包含的内容。然后你就能知道哪里出了问题。

两种方法:

  1. 在调用fopen之前打印出值

  2. 使用调试器，在fopen调用上设置断点并检查文件路径

从\判断，我猜你是在windows上。

试试这个函数:

#include <windows.h>
bool fileExist(const std::string& fileName_in)
{ 
  DWORD ftyp = GetFileAttributesA(fileName_in.c_str());
  if (ftyp == INVALID_FILE_ATTRIBUTES)
    return false;
  if (ftyp & FILE_ATTRIBUTE_DIRECTORY)
    return false;   // this is a directory
  return true;      // this is a normal file
}

用这个函数尝试输入字符串。如果返回false，告诉用户他是盲人:)

看起来像是权限问题。您在其他子目录中尝试过吗?我添加了一些代码来检查fopen()返回时的errno值-注意下面的"Permission Denied":

> t
Please enter the file path:
> .test.cpp
File opened!
> t
Please enter the file path:
> c:setup.log
File failed to open with error: Permission denied
> t
Please enter the file path:
> c:cygwincygwin.bat
File opened!
>
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