c - 为什么我的 S_ISDIR 和 S_ISREG 不返回正确的目录/文件名？

Question

为什么我的 S_ISDIR 和 S_ISREG 不能返回正确的目录/文件名？

当我使用我用 3 个其他目录和一个文本文件创建的测试目录运行程序时，只有 Dir 的 printf() 执行。

#include "dirAssignment.h"

//Struct
typedef struct directories{

}directories;


//Method to look for directories and files:
void search(const char *fileName){
    struct stat dirInfo;
    struct dirent *dirp;
    DIR *dp;

    //Checks to see if there is an error with the fileName:
    if (lstat(fileName, &dirInfo) < 0)
        {
        //Error:
        printf("Something went wrong!\n");
        printf("%s\n",strerror(errno));
    }

    //Checks to see if file can be opened:
    if ((dp = opendir(fileName)) == NULL)
    {
        printf("Cannot open file %s\n", fileName);
        printf("%s\n", strerror(errno));
    }

    //If file can be opened, get all the files from the directory:
    while((dirp = readdir(dp)) != NULL)
    {   
        //Check for( and Ignore) parent and self:
        if (strcmp(dirp->d_name,".") == 0 || strcmp(dirp->d_name,"..") == 0)        
        {
            continue;
        }
        printf("%s:\t",dirp->d_name);


        if(S_ISDIR(dirInfo.st_mode))
        {
            printf("Dir\n");
        }
        else if(S_ISREG(dirInfo.st_mode))
        {
            printf("File\n");
        }
    /*
        else if(S_ISDIR(dirp->d_name, &dirInfo))
        {
            //stat(fileName, &dirInfo);

            //Checks to see if the file is a directory:
            if (S_ISDIR(getcwd(dirp->d_name,512).st_mode))
            {
                printf("directory in: %s\n", fileName);
            }
            //Must be a file:
            else if (S_ISREG(getcwd(dirp->d_name,512).st_mode))
            {
                printf("file in: %s\n", fileName);
            }
            //No clue how you got here!
            else
            {
                printf("Danger Will Robinson, Danger... Danger!!!\n");
            }
        }
        else
        {
            printf("Danger Will Robinson, Danger... Danger!!!\n");
        }
    */

     }//End of while loop
}//End of Search method

int main(int argc, char const *argv[])
{
    //Variables go here:
    int i = 0;
    char const *fileName = argv[1];


    //Prompt the user:
    printf("Enter starting fileName: %s\n",argv[1]);
    //Starting file:
    printf("Starting from file: %s\n...\n\n\n\n", fileName);

    //Lettuce(lol) find some files and directories!
    search(fileName);


    return 0;
}//End of main method

Answer 1

很明显你使用了错误的变量。 dirInfo是通过这一行初始化的 if (lstat(fileName, &dirInfo) < 0) 。这就是为什么总是打印 Dir。

   if(S_ISDIR(dirInfo.st_mode))
    {
        printf("Dir\n");
    }
    else if(S_ISREG(dirInfo.st_mode))
    {
        printf("File\n");
    }

在Linux上，也许你可以使用dirp->d_type获取类型。阅读this

如果想使用S_ISREG/S_ISDIR，只需调用 lstat首先获取文件状态。