fileops/listdir_recursive.c

   1 /* compile with:
   2    gcc listdir_recursive.c -o listdir_recursive -Wall -W -Wextra -ansi -pedantic */
   3
   4 #include <dirent.h>
   5 #include <stdio.h>
   6 #include <stdlib.h>
   7 #include <string.h>
   8 #include <unistd.h>
   9
  10 int listdir(const char *path)
  11 {
  12     struct dirent *pdent;
  13     DIR *pdir;
  14     char *newpath = NULL;
  15     static unsigned int dirdepth = 0;
  16     unsigned int i;
  17
  18     /* open directory named by path, associate a directory stream
  19        with it and return a pointer to it
  20     */
  21     if ((pdir = opendir(path)) == NULL) {
  22         perror("opendir");
  23         return -1;
  24     }
  25
  26     /* get all directory entries */
  27     while((pdent = readdir(pdir)) != NULL) {
  28         /* indent according to the depth we are */
  29         for (i = 0; i < dirdepth; i++)
  30             printf("  ");
  31
  32         /* print current entry, or [entry] if it's a directory */
  33         if (pdent->d_type == DT_DIR)
  34             printf("[%s]\n", pdent->d_name);
  35         else
  36             printf("%s\n", pdent->d_name);
  37
  38         /* Is it a directory ? If yes, list it */
  39         if (pdent->d_type == DT_DIR
  40             && strcmp(pdent->d_name, ".")
  41             && strcmp(pdent->d_name, "..")) {
  42             dirdepth++;
  43
  44             /* allocate memory for new path
  45                don't forget +1 for the '\0'
  46              */
  47             if ((newpath = malloc(strlen(path) + strlen(pdent->d_name) + 2)) == NULL) {
  48                 perror("malloc");
  49                 return -1;
  50             }
  51
  52             /* construct new path */
  53             strcpy(newpath, path);
  54             strcat(newpath, "/");
  55             strcat(newpath, pdent->d_name);
  56
  57             /* to iterate is human, to recurse, divine */
  58             if (listdir(newpath) == -1) {
  59                 closedir(pdir);
  60                 free(newpath);
  61                 return -1;
  62             }
  63         }
  64     }
  65
  66     closedir(pdir);
  67     if (newpath != NULL)
  68         free(newpath);
  69
  70     dirdepth--;
  71     return 1;
  72 }
  73
  74 int main(int argc, char *argv[])
  75 {
  76     /* check argument count */
  77     if (argc != 2) {
  78         fprintf(stderr, "Usage: %s directory\n", argv[0]);
  79         exit(EXIT_FAILURE);
  80     }
  81
  82     (void)listdir(argv[1]);
  83
  84     return EXIT_SUCCESS;
  85 }