checking directory paths ends with ".", ".." - c

Question

I have a programming problem that I hope someone out there can help me with. I am trying to learn C programming for a task at work and I have set myself a little project, which consists of reading down a file tree including all the sub directories obtaining information about each file.
The problem I get is that my program dosen't ignore the directory path ends with either /. or /.. and when it prints all the directories, I want to give space in front of the subdirectories for the readablity.
so the error is occured at this part:
int isDir(const char *parent, char *name) {
struct stat st_buf; // file info
char buf[BUF_SIZE];
if (strcmp(name, ".") == 0 || strcmp(name, "..") == 0) {
return 0;
}
char *path = malloc(strlen(name) + strlen(parent) + 2);
//sprintf(char *buf, const char *format, [arg1],[arg2],...)
sprintf(path, "%s/%s", parent, name);
stat(path, &st_buf); //
return S_ISDIR(st_buf.st_mode); //directory
}
And this is main and list function:
int list(const char *name) {
DIR *dirp = opendir(name);
struct dirent *dentry;
char buf[BUF_SIZE];
while ((dentry = readdir(dirp)) != NULL) {
char *dir_name = dentry->d_name;
printf(" %s\n", dir_name);
//if it's dir, then go into dir
if (isDir(name, dir_name)) { //name : parent, dir_name : child
chdir(dir_name);
getcwd(buf, BUF_SIZE);
list(buf);
}
}
closedir(dirp);
}
int main()
{
list(".");
return 0;
}
The result is like this:
hm1.c
Data
lab1.txt
result1
lab3.txt
.
..
.
..
result2
lab3.txt
.
..
result3
lab3.txt
.
..
a.c
.
..
a.out
result I want to print
hm1.c
Data
lab1.txt
result1
lab3.txt
result2
lab3.txt
result3
lab3.txt
a.c
a.out

Answer 1

Your isDir is returning true/false where it returns false (or zero) if you have . oe .. and then the true/false value of S_ISDIR in other cases
What you really need is the function to return one of 3 values SKIP, isFILE or isDIR and then write your print logic based on that.
You also need to fix your memory leaks
Also note that chdir(dir_name); changes the actual directory of the process, so once you return fromlist within your loop you will no longer be able to open the files or directories that you are looping over (because you are now in a different directory)
This will fix your problems and print the format you want
enum { doSkip, isFile, isDir } testDir(char *path, char *name)
{
struct stat st_buf;
if (strcmp(name, ".") == 0 || strcmp(name, "..") == 0) {
return doSkip;
}
stat(path, &st_buf);
if (S_ISDIR(st_buf.st_mode))
return isDir;
return isFile;
}
void list(const char *path, int indentlevel)
{
DIR *dirp = opendir(path);
struct dirent *dentry;
char buf[10000]; // Lets just make the buffer sufficently big for this example
if (!dirp) {
printf("%*sNo access\n",indentlevel,"");
return;
}
while ((dentry = readdir(dirp)) != NULL) {
sprintf(buf,"%s/%s", path, dentry->d_name);
switch (testDir(buf,dentry->d_name)) {
case doSkip:
/* do nothing */
break;
case isDir:
printf("%*s%s:\n",indentlevel,"",dentry->d_name);
list(buf,indentlevel+4);
break;
case isFile:
printf("%*s%s\n",indentlevel,"",dentry->d_name);
break;
}
}
closedir(dirp);
}
int main()
{
list(".", 0);
return 0;
}

Answer 2

Another way to do it, if you're willing to go to C++, is to use std::experimental::filesystem, also (mostly) known as Boost.Filesystem. With that, you would do something like:
#include <experimental/filesystem> // Could substitute <boost/filesystem.hpp>
#include <boost/range/iterator_range.hpp>
#include <iostream>
using namespace std::experimental;
int main(int argc, char *argv[])
{
const auto path = filesystem::path{ argc > 1 ? argv[1] : "." };
if( filesystem::is_directory(path) )
{
std::cout << path << " is a directory containing:\n";
for( const auto& entry : boost::make_iterator_range( filesystem::recursive_directory_iterator{path}, {} ) )
{
std::cout << entry << "\n";
}
}
}
See it run here. Note that the directory iterators automatically skip . and ...