#define _POSIX_C_SOURCE 200809L
#define _GNU_SOURCE
#include <stdlib.h>
#include <locale.h>
#include <ftw.h>
#include <string.h>
#include <stdio.h>
#include <errno.h>
struct entry {
char *name;
char pathname[];
};
struct listing {
size_t max;
size_t num;
struct entry **ent;
};
#define STRUCT_LISTING_INITIALIZER { 0, 0, NULL }
static int entrysort(const void *ptr1, const void *ptr2)
{
const struct entry *ent1 = *(const struct entry **)ptr1;
const struct entry *ent2 = *(const struct entry **)ptr2;
return strcoll(ent1->pathname, ent2->pathname);
}
static struct listing *nftw_listing = NULL;
static int nftw_add(const char *pathname, const struct stat *info, int typeflag, struct FTW *ftwbuf)
{
const char *name = pathname + ftwbuf->base;
(void)info;
(void)typeflag;
if (name[0] == '.' && !name[1])
return 0;
if (name[0] == '.' && name[1] == '.' && !name[2])
return 0;
if (nftw_listing->num >= nftw_listing->max) {
const size_t new_max = nftw_listing->num + 1000;
struct entry **new_ent;
new_ent = realloc(nftw_listing->ent, new_max * sizeof (struct entry *));
if (!new_ent)
return -ENOMEM;
nftw_listing->max = new_max;
nftw_listing->ent = new_ent;
}
const size_t pathnamelen = strlen(pathname);
struct entry *ent;
ent = malloc(sizeof (struct entry) + pathnamelen + 1);
if (!ent)
return -ENOMEM;
memcpy(ent->pathname, pathname, pathnamelen + 1);
ent->name = ent->pathname + ftwbuf->base;
nftw_listing->ent[nftw_listing->num++] = ent;
return 0;
}
int scan_tree_sorted(struct listing *list, const char *path)
{
if (!list) {
errno = EINVAL;
return -1;
}
if (!path || !*path) {
errno = ENOENT;
return -1;
}
nftw_listing = list;
int result = nftw(path, nftw_add, 64, FTW_DEPTH);
nftw_listing = NULL;
if (result < 0) {
errno = -result;
return -1;
} else
if (result > 0) {
errno = 0;
return result;
}
if (list->num > 2)
qsort(list->ent, list->num, sizeof list->ent[0], entrysort);
return 0;
}
int main(int argc, char *argv[])
{
struct listing list = STRUCT_LISTING_INITIALIZER;
setlocale(LC_ALL, "");
if (argc < 2 || !strcmp(argv[1], "-h") || !strcmp(argv[1], "--help")) {
const char *arg0 = (argc > 0 && argv && argv[0] && argv[0][0]) ? argv[0] : "(this)";
fprintf(stderr, "\n");
fprintf(stderr, "Usage: %s [ -h | --help ]\n", arg0);
fprintf(stderr, " %s .\n", arg0);
fprintf(stderr, " %s TREE [ TREE ... ]\n", arg0);
fprintf(stderr, "\n");
fprintf(stderr, "This program lists all files and directories starting at TREE,\n");
fprintf(stderr, "in sorted order.\n");
fprintf(stderr, "\n");
return EXIT_SUCCESS;
}
for (int arg = 1; arg < argc; arg++) {
if (scan_tree_sorted(&list, argv[arg])) {
fprintf(stderr, "%s: Error scanning directory tree: %s.\n", argv[arg], strerror(errno));
return EXIT_FAILURE;
}
}
printf("Found %zu entries:\n", list.num);
for (size_t i = 0; i < list.num; i++)
printf("\t%s\t(%s)\n", list.ent[i]->pathname, list.ent[i]->name);
return EXIT_SUCCESS;
}