osdir.hh

 
#ifndef OSLINK_OSDIR_HEADER_H_
#define OSLINK_OSDIR_HEADER_H_
 
 
#if defined(unix) || defined(__unix) || defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
#define OSLINK_OSDIR_POSIX
#elif defined(_WIN32)
#define OSLINK_OSDIR_WINDOWS
#else
#define OSLINK_OSDIR_NOTSUPPORTED
#endif
 
#include <string>
 
#if defined(OSLINK_OSDIR_NOTSUPPORTED)
 
namespace oslink
{
    class directory
    {
        public:
            directory(const std::string&)       { }
            operator void*() const              { return (void*)0; }
            std::string next()                  { return ""; }
    };
}
 
#elif defined(OSLINK_OSDIR_POSIX)
 
#include <sys/types.h>
#include <dirent.h>
 
namespace oslink
{
    class directory
    {
        public:
            directory(const std::string& aName)
                : handle(opendir(aName.c_str())), willfail(false)
                {
                    if (!handle)
                        willfail = true;
                    else
                    {
                        dirent* entry = readdir(handle);
                        if (entry)
                            current = entry->d_name;
                        else
                            willfail = true;
                    }
                }
            ~directory()
                {
                    if (handle)
                        closedir(handle);
                }
            operator void*() const
                {
                    return willfail ? (void*)0:(void*)(-1);
                }
            std::string next()
                {
                    std::string prev(current);
                    dirent* entry = readdir(handle);
                    if (entry)
                        current = entry->d_name;
                    else
                        willfail = true;
                    return prev;
                }
        private:
            DIR* handle;
            bool willfail;
            std::string current;
    };
}
 
#elif defined(OSLINK_OSDIR_WINDOWS)
 
#include <windows.h>
#include <winbase.h>
 
namespace oslink
{
    class directory
    {
        public:
            directory(const std::string& aName)
                : handle(INVALID_HANDLE_VALUE), willfail(false)
                {
                    // First check the attributes trying to access a non-directory with
                    // FindFirstFile takes ages
                    DWORD attrs = GetFileAttributes(aName.c_str());
                    if ( (attrs == 0xFFFFFFFF) || ((attrs && FILE_ATTRIBUTE_DIRECTORY) == 0) )
                    {
                        willfail = true;
                        return;
                    }
                    std::string Full(aName);
                    // Circumvent a problem in FindFirstFile with c:\\* as parameter
                    if ( (Full.length() > 0) && (Full[Full.length()-1] != '\\') )
                        Full += "\\";
                    WIN32_FIND_DATA entry;
                    handle = FindFirstFile( (Full+"*").c_str(), &entry);
                    if (handle == INVALID_HANDLE_VALUE)
                        willfail = true;
                    else
                        current = entry.cFileName;
                }
            ~directory()
                {
                    if (handle != INVALID_HANDLE_VALUE)
                        FindClose(handle);
                }
 
            operator void*() const
                {
                    return willfail ? (void*)0:(void*)(-1);
                }
            std::string next()
                {
                    std::string prev = current;
                    WIN32_FIND_DATA entry;
                    int ok = FindNextFile(handle, &entry);
                    if (!ok)
                        willfail = true;
                    else
                        current = entry.cFileName;
                    return current;
                }
        private:
            HANDLE  handle;
            bool    willfail;
            std::string current;
    };
}
 
 
#endif
 
 
#endif