ERROR: stat: No Such File Or Directory, opendir() and stat() in C programming

Question

Hey and thanks for reading.

I am making a program which takes 1 argument (directory) and reads all the files in the directory used opendir()/readdir(), and displays the file type (reg, link, directory etc) using stat. I am receiving the error "No Such file or Directory" when I execute me program in the shell (I am using redhat linux). Here is my code:

#define _BSD_SOURCE
#include <stdio.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <time.h>
#include <stdio.h>
#include <stdlib.h>

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

    DIR *dirp;
    struct dirent* dent;
    struct stat info;

//If no args
    if(argc == 1){

        argv[1] = ".";  

            dirp=opendir(argv[1]); // specify directory here: "." is the "current directory"
            do {
                dent = readdir(dirp);
                if (dent)
                {
//////////////////////////////////////////////////////////////////////////
               if (stat(dent->d_name, &info) == -1) {
               perror("stat");
               exit(EXIT_FAILURE);
           }

           switch (info.st_mode & S_IFMT) {
           case S_IFBLK:  printf("block device\n");            break;
           case S_IFCHR:  printf("character device\n");        break;
           case S_IFDIR:  printf("dir ");                      break;
           case S_IFIFO:  printf("FIFO/pipe\n");               break;
           case S_IFLNK:  printf("lnk ");                      break;
           case S_IFREG:  printf("reg ");                      break;
           case S_IFSOCK: printf("socket\n");                  break;
           default:       printf("unknown?\n");                break;
           }

//////////////////////////////////////////////////////////////////////////

                    printf("%s \n", dent->d_name);

                }
            } while (dent);
            closedir(dirp);

       }

////////////////////////////////////////////////////////////////////////////////////////////////
//If specified directory    
    if(argc > 1){

        dirp=opendir(argv[1]); // specify directory here: "." is the "current directory"
        do {
            dent = readdir(dirp);
            if (dent)
            {

/////////////////////////////////////////////////////////////////////////////////////           
               if (stat(dent->d_name, &info) == -1) {
               perror("stat");
               exit(EXIT_FAILURE);
           }



           switch (info.st_mode & S_IFMT) {
           case S_IFBLK:  printf("block device\n");            break;
           case S_IFCHR:  printf("character device\n");        break;
           case S_IFDIR:  printf("dir ");                      break;
           case S_IFIFO:  printf("FIFO/pipe\n");               break;
           case S_IFLNK:  printf("lnk ");                      break;
           case S_IFREG:  printf("reg ");                      break;
           case S_IFSOCK: printf("socket\n");                  break;
           default:       printf("unknown?\n");                break;
           }
//////////////////////////////////////////////////////////////////////////////////////
//           printf("%s\n", argv[1]);

                printf("%s \n", dent->d_name);
            }
        } while (dent);
        closedir(dirp);

   } 
return 0;    
}

Any ideas? I'm a bit stuck. Thanks for your input

Also, are files of type "Link" going to be output using stat, or do I have to use lstat? Not sure how to use lstat in this situation, if I change the struct type to "struct lstat info" it throws an error.

Answer 1

dent->d_name is the name of the file relative to your current directory (e.g "/home/barney/myfile.txt") not the absolute full path to the file (e.g. /home/barney/sources/myfile.txt), which is the one expected by stat.

This is why stat cant find the path. print dent->d_name before each call to stat to observe those incorrect paths.

Edit: You can try chdir() to change your working directory to argv[1]