c - 检查文件是否存在于c中

Question

1. prgchDirPath 是字符指针。但预期的是 LPCWSTR。如何改变这个？

2. prgchDirPath 是目录路径。文件不存在。但我想确定目录/路径是否存在。下面的 API 可以帮助我吗？如果是，如何？

   unsigned char IsFilePathCorrect(char* prgchDirPath)
   {
           WIN32_FIND_DATA FindFileData;
           HANDLE handle;
           int found=0;
   
           //1. prgchDirPath is char pointer. But expected is LPCWSTR.
           //How to change this?
           //2. prgchDirPath is a directory path. File is not existed.
           //But I want to make sure if directory/path exists or not.
           //Can the API below helps me? if yes, how?
           handle = FindFirstFile(prgchDirPath, &FindFileData);
           if(handle != INVALID_HANDLE_VALUE)
           found = 1;
           if(found) 
           {
               FindClose(handle);
           }
           return found;
   }
   

我想检查目录路径是否存在。请提供一个示例代码。谢谢你。

Answer 1

您可以简单地使用access，它在 Windows、Linux、Mac 等上得到广泛支持：如果文件存在则access(filepath, 0)返回0，否则返回错误代码。在 Windows 上，您将需要#include <io.h>.

Answer 2

如何使用getAttributes函数这样做：-

BOOL DirectoryExists(LPCTSTR szPath)
{
  DWORD dwAttrib = GetFileAttributes(szPath);

  return (dwAttrib != INVALID_FILE_ATTRIBUTES && 
         (dwAttrib & FILE_ATTRIBUTE_DIRECTORY));
}

或者你也可以试试这个：-

#include <io.h>     // For access().
#include <sys/types.h>  // For stat().
#include <sys/stat.h>   // For stat().

bool DirectoryExists( const char* path){

    if( _access( path, 0 ) == 0 ){

        struct stat s;
        stat( path, &s);

        return (s.st_mode & S_IFDIR) != 0;
    }
    return false;
}

Answer 3

#include<stdio.h>
#include<fcntl.h>

#define DEVICE "test.txt"

int main()
{
    int value = 0;
    if(access(DEVICE, F_OK) == -1) {
        printf("file %s not present\n",DEVICE);
        return 0;
    }
    else
        printf("file %s present, will be used\n",DEVICE);
    return 0;
}

Answer 4

您可以在不使用任何 Windows API 的情况下检查路径是否正确，如下所示

    /*
     * Assuming that prgchDirPath is path to a directory
     * and not to any file.
     */
    unsigned char IsFilePathCorrect(char* prgchDirPath)
    {
        FILE *fp;
        char path[MAX_PATH] = {0};

        strcpy(path, prgchDirPath);
        strcat(path, "/test.txt");

        fp = fopen(path, "w");
        if (fp == NULL)
            return 0;

        fclose(fp);
        return 1;
    }