How to search a path for files with a specific patern

Question

I am looking for a way to find files in a directory ( and its subdirectories) if the files matches to a pattern.

I have this code:

 inline static void ScanForFiles(std::vector<string> &files,const path &inputPath,string filter="*.*",bool recursive=false)
 {
        typedef vector<boost::filesystem::path> vec;             // store paths,
        vec v;                                // so we can sort them later

        copy(directory_iterator(inputPath), directory_iterator(), back_inserter(v));
        for(int i=0; i<v.size(); i++)
        {
            if(IsDirectory(v[i]))
            {
                if(recursive)
                {
                    ScanForDirs(files,v[i],recursive);
                }
            }
            else
            {
                if(File::IsFile(v[i]))
                {
                    files.push_back(v[i].string());
                }
            }
        }
}

This is working, but it doesn't match pattenrs. For example I want to call this function like this:

std::vector<string> files;
ScanForFiles(files,"c:\\myImages","*.jpg",true);

and I get the list of all jpeg images in myimages and all of its subfolders.

The current code returns all images and there is no pattern match.

How can I change the above code to do so?

This looks like a duplicate of http://stackoverflow.com/questions/1257721/can-i-use-a-mask-to-iterate-files-in-a-directory-with-boost — ales_t, Dec 23 '13 at 18:10
@ales_t: The problem is converting filters from normal type of "\*.jpg" to a regex format. Something such as this is regex filter("*.jpg") doesn't work. I need ask user of this function to write the filter in regex format which is not good, or convert it which it seems I can not. Any solution? — mans, Dec 23 '13 at 18:25
You can try writing a function which converts wildcards to regexes. As long as you only support `*` and `?`, you can just escape the pattern and then replace `\*` with `.*` and `\?` with `.?`, see here: http://www.codeproject.com/Articles/11556/Converting-Wildcards-to-Regexes — ales_t, Dec 23 '13 at 18:31
On the other hand, e.g. bash wildcards are much richer and writing a conversion function which handles all of their features could be tricky. — ales_t, Dec 23 '13 at 18:33
@ales_t: what about ( ) { } < > and so on, I think they should be converted too. — mans, Dec 23 '13 at 18:41

score 0 · Answer 1 · edited May 23 '17 at 12:19

I've come up with the following snippet:

#include <iostream>
#include <string>
#include <boost/regex.hpp>

std::string escapeRegex(const std::string &str) {
  boost::regex esc("([\\^\\.\\$\\|\\(\\)\\[\\]\\*\\+\\?\\/\\\\])");                                                         
  std::string rep("\\\\\\1");
  return regex_replace(str, esc, rep, boost::match_default | boost::format_sed);
}

std::string wildcardToRegex(const std::string &pattern) {
  boost::regex esc("\\\\([\\*\\?])");
  std::string rep(".\\1");
  return regex_replace(escapeRegex(pattern), esc, rep, boost::match_default | boost::format_sed);
}

using namespace std;
using namespace boost;
int main(int argc, char **argv) {
  string pattern = "test/of regexes/*.jpg";
  cout << wildcardToRegex(pattern) << endl;
}

It is heavily based on this question. I hope this helps.

How to search a path for files with a specific patern

1 Answers1