fileops/listdir_recursive.c

   1 /*
   2  * Compile with:
   3  * gcc listdir_recursive.c -o listdir_recursive -Wall -W -Wextra -ansi -pedantic
   4  */
   5
   6 #include <dirent.h>
   7 #include <stdio.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <unistd.h>
  11
  12 /*
  13  * Since listdir() uses a static variable to keep track of the call depth,
  14  * it is not safe to use it in a multi threading environment. If this is the
  15  * case, then you need to pass 'dirdepth' as an argument to listdir().
  16  */
  17 int listdir(const char *path)
  18 {
  19     struct dirent *pdent;
  20     DIR *pdir;
  21     char *newpath = NULL;
  22     static unsigned int dirdepth = 0;
  23     unsigned int i;
  24
  25     /*
  26      * Open directory named by path, associate a directory stream
  27      * with it and return a pointer to it
  28     */
  29     if ((pdir = opendir(path)) == NULL) {
  30         perror("opendir");
  31         return -1;
  32     }
  33
  34     /* Get all directory entries */
  35     while((pdent = readdir(pdir)) != NULL) {
  36         /* Indent according to the depth we are */
  37         for (i = 0; i < dirdepth; i++)
  38             printf("  ");
  39
  40         /* Print current entry, or [entry] if it's a directory */
  41         if (pdent->d_type == DT_DIR)
  42             printf("[%s]\n", pdent->d_name);
  43         else
  44             printf("%s\n", pdent->d_name);
  45
  46         /* Is it a directory ? If yes, list it */
  47         if (pdent->d_type == DT_DIR
  48             && strcmp(pdent->d_name, ".")
  49             && strcmp(pdent->d_name, "..")) {
  50             dirdepth++;
  51
  52             /* Allocate memory for new path (don't forget +1 for the '\0') */
  53             if ((newpath = malloc(strlen(path) + strlen(pdent->d_name) + 2)) == NULL) {
  54                 perror("malloc");
  55                 return -1;
  56             }
  57
  58             /* Construct new path */
  59             strcpy(newpath, path);
  60             strcat(newpath, "/");
  61             strcat(newpath, pdent->d_name);
  62
  63             /* To iterate is human, to recurse, divine */
  64             if (listdir(newpath) == -1) {
  65                 closedir(pdir);
  66                 free(newpath);
  67                 return -1;
  68             }
  69         }
  70     }
  71
  72     closedir(pdir);
  73     if (newpath != NULL)
  74         free(newpath);
  75
  76     dirdepth--;
  77     return 1;
  78 }
  79
  80 int main(int argc, char *argv[])
  81 {
  82     /* Check argument count */
  83     if (argc != 2) {
  84         fprintf(stderr, "Usage: %s directory\n", argv[0]);
  85         exit(EXIT_FAILURE);
  86     }
  87
  88     (void)listdir(argv[1]);
  89
  90     return EXIT_SUCCESS;
  91 }