Solution for Exercise 23-4

ex2304

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

int main()
{
    DIR *folder;
    struct dirent *file;
    struct stat filestat;

    folder=opendir(".");
    if(folder==NULL)
    {
        puts("Unable to read directory");
        exit(1);
    }
    while( (file = readdir(folder)) != NULL )
    {
      stat(file->d_name,&filestat);
      if( S_ISDIR(filestat.st_mode) )
      {
          printf("%-14s %-5s %s",
                  file->d_name,
                  "<DIR>",
                  ctime(&filestat.st_mtime));
      }
      else
      {
          printf("%-14s %5ld %s",
                file->d_name,
                filestat.st_size,
                ctime(&filestat.st_mtime));
      }
    }
    closedir(folder);
    return(0);
}

Output

.              <DIR> Thu May 21 21:27:11 2020
..             <DIR> Thu May 21 15:08:14 2020
listing2305.c    355 Thu May 21 15:36:29 2020
ex2303.c         564 Thu May 21 21:27:10 2020
listing2301.c    350 Thu May 21 15:32:52 2020
listing2306.c    222 Thu May 21 15:37:01 2020
listing2302.c    558 Thu May 21 21:22:12 2020
ex2301.c         350 Thu May 21 20:49:38 2020
a.out          12924 Thu May 21 21:27:11 2020
listing2303.c    357 Thu May 21 15:34:55 2020
ex2302.c         360 Thu May 21 20:57:01 2020
listing2304.c    381 Thu May 21 15:35:48 2020
ex2304.c         692 Thu May 21 21:41:21 2020

Notes

* Multiple solutions are possible for this code, so don't accept my solution as the only one!

* I put the the S_ISDIR macro to work at Line 22. The if condition returns TRUE if a directory is found, so I stuffed the printf() function that follows at Line 24 with the text <DIR> inside as an immediate value. Otherwise, the else part of the decision is executed, which looks similar to the code from Exercise 23-3.

* You can read more about file permissions and the related defined constants and macros in my blog series on file permissions here.

Exercise ex2305 →