How to delete a non empty folder using unlinkat() in c?
Here is my work on it:
/*
* Program to erase the files/subfolders in a directory given as an input
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <dirent.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
void remove_dir_content(const char *path)
{
struct dirent *de;
char fname[300];
DIR *dr = opendir(path);
if(dr == NULL)
{
printf("No file or directory found\n");
return;
}
while((de = readdir(dr)) != NULL)
{
int ret = -1;
struct stat statbuf;
sprintf(fname,"%s/%s",path,de->d_name);
if (!strcmp(de->d_name, ".") || !strcmp(de->d_name, ".."))
continue;
if(!stat(fname, &statbuf))
{
if(S_ISDIR(statbuf.st_mode))
{
printf("Is dir: %s\n",fname);
printf("Err: %d\n",ret = unlinkat(dirfd(dr),fname,AT_REMOVEDIR));
if(ret != 0)
{
remove_dir_content(fname);
printf("Err: %d\n",ret = unlinkat(dirfd(dr),fname,AT_REMOVEDIR));
}
}
else
{
printf("Is file: %s\n",fname);
printf("Err: %d\n",unlink(fname));
}
}
}
closedir(dr);
}
void main()
{
char str[10],str1[20] = "../",fname[300]; // Use str,str1 as your directory path where it's files & subfolders will be deleted.
printf("Enter the dirctory name: ");
scanf("%s",str);
strcat(str1,str);
printf("str1: %s\n",str1);
remove_dir_content(str1); //str1 indicates the directory path
}
The easiest way to do this is with remove_all function of the Boost.Filesystem library. Besides, the resulting code will be portable.
If you want to write something specific for Unix (rmdir) or for Windows (RemoveDirectory) then you'll have to write a function that deletes are subfiles and subfolders recursively.
EDIT
Looks like this question was already asked, in fact someone already recommended Boost's remove_all. So please don't upvote my answer.
If you are using a POSIX compliant OS, you could use nftw() for file tree traversal and remove (removes files or directories). If you are in C++ and your project uses boost, it is not a bad idea to use the Boost.Filesystem as suggested by Manuel.
In the code example below I decided not to traverse symbolic links and mount points (just to avoid a grand removal:) ):
#include <stdio.h>
#include <stdlib.h>
#include <ftw.h>
static int rmFiles(const char *pathname, const struct stat *sbuf, int type, struct FTW *ftwb)
{
if(remove(pathname) < 0)
{
perror("ERROR: remove");
return -1;
}
return 0;
}
int main(int argc, char *argv[])
{
if (argc != 2)
{
fprintf(stderr,"usage: %s path\n",argv[0]);
exit(1);
}
// Delete the directory and its contents by traversing the tree in reverse order, without crossing mount boundaries and symbolic links
if (nftw(argv[1], rmFiles,10, FTW_DEPTH|FTW_MOUNT|FTW_PHYS) < 0)
{
perror("ERROR: ntfw");
exit(1);
}
return 0;
}
//======================================================
// Recursely Delete files using:
// Gnome-Glib & C++11
//======================================================
#include <iostream>
#include <string>
#include <glib.h>
#include <glib/gstdio.h>
using namespace std;
int DirDelete(const string& path)
{
const gchar* p;
GError* gerr;
GDir* d;
int r;
string ps;
string path_i;
cout << "open:" << path << "\n";
d = g_dir_open(path.c_str(), 0, &gerr);
r = -1;
if (d) {
r = 0;
while (!r && (p=g_dir_read_name(d))) {
ps = string{p};
if (ps == "." || ps == "..") {
continue;
}
path_i = path + string{"/"} + p;
if (g_file_test(path_i.c_str(), G_FILE_TEST_IS_DIR) != 0) {
cout << "recurse:" << path_i << "\n";
r = DirDelete(path_i);
}
else {
cout << "unlink:" << path_i << "\n";
r = g_unlink(path_i.c_str());
}
}
g_dir_close(d);
}
if (r == 0) {
r = g_rmdir(path.c_str());
cout << "rmdir:" << path << "\n";
}
return r;
}
C++17 has <experimental\filesystem> which is based on the boost version.
Use std::experimental::filesystem::remove_all to remove recursively.
If you need more control, try std::experimental::filesystem::recursive_directory_iterator.
You can also write your own recursion with the non-resursive version of the iterator.
namespace fs = std::experimental::filesystem;
void IterateRecursively(fs::path path)
{
if (fs::is_directory(path))
{
for (auto & child : fs::directory_iterator(path))
IterateRecursively(child.path());
}
std::cout << path << std::endl;
}
You can use opendir and readdir to read directory entries and unlink to delete them.
Many unix-like systems (Linux, the BSDs, and OS X, at the very least) have the fts functions for directory traversal.
To recursively delete a directory, perform a depth-first traversal (without following symlinks) and remove every visited file:
int recursive_delete(const char *dir)
{
int ret = 0;
FTS *ftsp = NULL;
FTSENT *curr;
// Cast needed (in C) because fts_open() takes a "char * const *", instead
// of a "const char * const *", which is only allowed in C++. fts_open()
// does not modify the argument.
char *files[] = { (char *) dir, NULL };
// FTS_NOCHDIR - Avoid changing cwd, which could cause unexpected behavior
// in multithreaded programs
// FTS_PHYSICAL - Don't follow symlinks. Prevents deletion of files outside
// of the specified directory
// FTS_XDEV - Don't cross filesystem boundaries
ftsp = fts_open(files, FTS_NOCHDIR | FTS_PHYSICAL | FTS_XDEV, NULL);
if (!ftsp) {
fprintf(stderr, "%s: fts_open failed: %s\n", dir, strerror(errno));
ret = -1;
goto finish;
}
while ((curr = fts_read(ftsp))) {
switch (curr->fts_info) {
case FTS_NS:
case FTS_DNR:
case FTS_ERR:
fprintf(stderr, "%s: fts_read error: %s\n",
curr->fts_accpath, strerror(curr->fts_errno));
break;
case FTS_DC:
case FTS_DOT:
case FTS_NSOK:
// Not reached unless FTS_LOGICAL, FTS_SEEDOT, or FTS_NOSTAT were
// passed to fts_open()
break;
case FTS_D:
// Do nothing. Need depth-first search, so directories are deleted
// in FTS_DP
break;
case FTS_DP:
case FTS_F:
case FTS_SL:
case FTS_SLNONE:
case FTS_DEFAULT:
if (remove(curr->fts_accpath) < 0) {
fprintf(stderr, "%s: Failed to remove: %s\n",
curr->fts_path, strerror(curr->fts_errno));
ret = -1;
}
break;
}
}
finish:
if (ftsp) {
fts_close(ftsp);
}
return ret;
}
Source: Stackoverflow.com