1   │ #include <stdio.h>
   2   │ #include <dirent.h>
   3   │ #include <sys/types.h>
   4   │ #include <sys/stat.h>
   5   │ #include <fcntl.h>
   6   │ #include <stdlib.h>
   7   │ #include <limits.h>
   8   │ #include <ctype.h>
   9   │ #include <unistd.h>
  10   │ #include <string.h>
  11   │
  12   │ int cmp(const void* a, const void* b) {
  13   │     const char* A = *(const char**)a;
  14   │     const char* B = *(const char**)b;
  15   │     return strcasecmp(A, B);
  16   │ }
  17   │
  18   │ char gbuf[PATH_MAX];
  19   │
  20   │ void traverse(char* dir, char* myname, int size) {
  21   │     DIR* d = opendir(dir);
  22   │     if (d) {
  23   │         char** names = NULL;
  24   │         int a = 0, u = 0;
  25   │
  26   │         if (myname) {
  27   │             printf("cd %s\n", myname);
  28   │         }
  29   │
  30   │         struct dirent* dd;
  31   │         while ((dd = readdir(d))) {
  32   │             if (strcmp(dd->d_name, ".") && strcmp(dd->d_name, "..")) {
  33   │                 char buf[PATH_MAX];
  34   │                 if (snprintf(buf, sizeof(buf), "%s/%s", dir, dd->d_name) < sizeof(buf)) {
  35   │                     struct stat stb;
  36   │                     if (lstat(buf, &stb) >= 0 && S_ISDIR(stb.st_mode)) {
  37   │                         if (u == a) {
  38   │                             if (!(a *= 2)) a = 64;
  39   │                             names = realloc(names, a * sizeof(names[0]));
  40   │                             if (!names) abort();
  41   │                         }
  42   │                         names[u++] = strdup(dd->d_name);
  43   │                     }
  44   │                 }
  45   │             }
  46   │         }
  47   │         closedir(d);
  32   │             if (strcmp(dd->d_name, ".") && strcmp(dd->d_name, "..")) {
  33   │                 char buf[PATH_MAX];
  34   │                 if (snprintf(buf, sizeof(buf), "%s/%s", dir, dd->d_name) < sizeof(buf)) {
  35   │                     struct stat stb;
  36   │                     if (lstat(buf, &stb) >= 0 && S_ISDIR(stb.st_mode)) {
  37   │                         if (u == a) {
  38   │                             if (!(a *= 2)) a = 64;
  39   │                             names = realloc(names, a * sizeof(names[0]));
  40   │                             if (!names) abort();
  41   │                         }
  42   │                         names[u++] = strdup(dd->d_name);
  43   │                     }
  44   │                 }
  45   │             }
  46   │         }
  47   │         closedir(d);
  48   │
  49   │         qsort(names, u, sizeof(names[0]), cmp);
  50   │         for (int i = 0; i < u; ++i) {
  51   │             int new_size = size + 1 + strlen(names[i]);
  52   │             dir[size] = '/';
  53   │             memcpy(dir + size + 1, names[i], strlen(names[i]) + 1);
  54   │             traverse(dir, names[i], new_size);
  55   │             dir[size] = '\0';
  56   │         }
  57   │
  58   │         free(names);
  59   │
  60   │         if (myname) {
  61   │             printf("cd ..\n");
  62   │         }
  63   │     }
  64   │ }
  65   │
  66   │ int main(int argc, char* argv[]) {
  67   │     memset(gbuf, 0, sizeof(gbuf));
  68   │     if (strlen(argv[1]) < sizeof(gbuf)) {
  69   │         memcpy(gbuf, argv[1], strlen(argv[1]));
  70   │         traverse(gbuf, NULL, strlen(gbuf));
  71   │     }
  72   │ }