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#define _GNU_SOURCE
#include <dirent.h> /* Defines DT_* constants */
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <sys/syscall.h>
#define handle_error(msg) \
do { perror(msg); exit(EXIT_FAILURE); } while (0)
struct linux_dirent {
long d_ino;
off_t d_off;
unsigned short d_reclen;
char d_name[];
};
#define BUF_SIZE (1024 * 1024 * 5)
void listdir(const char * dirname)
{
int fd, nread;
struct linux_dirent *d;
int bpos;
char d_type;
char * buf = malloc(BUF_SIZE);
fd = open(dirname, O_RDONLY | O_DIRECTORY);
if (fd == -1)
handle_error("open");
for ( ; ; ) {
nread = syscall(SYS_getdents, fd, buf, BUF_SIZE);
if (nread == -1)
handle_error("getdents");
if (nread == 0)
break;
for (bpos = 0; bpos < nread;) {
d = (struct linux_dirent *) (buf + bpos);
d_type = *(buf + bpos + d->d_reclen - 1);
bpos += d->d_reclen;
if(d->d_ino && strcmp(d->d_name, ".") && strcmp(d->d_name, ".."))
{
if(d_type == DT_DIR)
{
printf("%s/%s\n",dirname, d->d_name);
int dirname_len = strlen(dirname);
char * subdir = calloc(1, PATH_MAX + 1);
strcat(subdir, dirname);
strcat(subdir + dirname_len, "/");
strcat(subdir + dirname_len + 1, d->d_name);
listdir(subdir);
free(subdir);
}
}
}
}
close(fd);
free(buf);
}
int
main(int argc, char *argv[])
{
listdir(argc > 1 ? argv[1] : ".");
exit(EXIT_SUCCESS);
}
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