File Search c++ - c++

Question

what is the best way of searching files on windows in c++. Should I use boost or there is a better way . I'm encountering some problems with building filesystem library. I found this:
#include <stdio.h>
#include <dir.h>
#include <string.h>
#define ALL_ATTS (FA_DIREC | FA_ARCH)
void walker(const char *, const char *);
void walker(const char *path, const char *findme)
{
struct ffblk finder;
unsigned int res;
chdir(path);
for (res = findfirst("*.*", &finder, ALL_ATTS); res == 0; res = findnext(&finder))
{
if (strcmp(finder.ff_name, ".") == 0) continue; /* current dir */
if (strcmp(finder.ff_name, "..") == 0) continue; /* parent dir */
/*
* If its a directory, examine it
* else compare the filename with the one we're looking for
*/
if (finder.ff_attrib & FA_DIREC)
{
char newpath[MAXPATH];
strcpy(newpath, path);
strcat(newpath, "\\");
strcat(newpath, finder.ff_name);
chdir(finder.ff_name);
walker(newpath, findme);
chdir("..");
}
else
{
if (strcmp(finder.ff_name, findme) == 0)
{
printf("Found in: %s\n", path);
}
}
}
}
int main(void)
{
const char *root = "\\";
char buf[BUFSIZ];
printf ("This program will find a file on the current drive.\n"
"Enter the name of the file to look for: ");
fflush(stdout);
if (fgets(buf, sizeof(buf), stdin))
{
strtok(buf, "\n"); /* Remove the newline character */
walker(root, buf);
}
return(0);
}
But none of the versions of dir headers works ...

Answer 1

I've found boost::filesystem to work quite well, as long as you know what you are doing. The following works for me:
#include <iostream>
#include <string>
#include "boost/filesystem.hpp"
namespace fs = boost::filesystem;
int _tmain(int argc, _TCHAR* argv[])
{
const std::string start = "C:\\";
const std::string findme = "winsock.dll";
fs::recursive_directory_iterator end;
fs::recursive_directory_iterator rdi(start);
while(rdi != end)
{
const std::string path = rdi->path().string();
if(path.find(findme) != std::string::npos)
{
std::cout << path << std::endl;
}
try
{
++rdi; // various system directories can bork this
}
catch(fs::filesystem_error e)
{
rdi.no_push(); // don't try to recurse into it
++rdi;
}
}
return 0;
}

Answer 2

You may want to consider Win32 APIs like FindFirstFile,FindNextFile, etc.
There are some sample codes on MSDN, like this.

Answer 3

You may want to have a look at the recls library made by Matthew Wilson.

Answer 4

The code you've found looks like it uses functions specific to some particular "standard" library (and may even have been written for MS-DOS). Secondarily, it uses a depth-first search; for directory searching, I usually prefer a breadth-first search.
I'd try to use Windows desktop search and/or Windows Search as the first choices. These will use pre-built indexes for really fast results if the user has that enabled.
If that's not available, I'd use code for a breadth-first search, which looks roughly like this:
#include <windows.h>
#include <queue>
#include <sstream>
#include <iostream>
#include <algorithm>
// I think MS's names for some things are obnoxious.
const HANDLE HNULL = INVALID_HANDLE_VALUE;
const int A_DIR = FILE_ATTRIBUTE_DIRECTORY;
std::ostream &operator<<(std::ostream &os, FILETIME const &ft) {
SYSTEMTIME utc, lt;
FileTimeToSystemTime(&ft, &utc);
SystemTimeToTzSpecificLocalTime(NULL, &utc, &lt);
return os << lt.wHour << ":" << lt.wMinute << ":" << lt.wSecond << "." << lt.wMilliseconds;
}
void process(std::string const &path, WIN32_FIND_DATA const &file) {
std::cout << file.ftCreationTime << "\t" << path << file.cFileName << "\n";
}
void find_file(std::string const &folder_name, std::string const &fmask) {
HANDLE finder; // for FindFirstFile
WIN32_FIND_DATA file; // data about current file.
std::priority_queue<std::string, std::vector<std::string>, std::greater<std::string> > dirs;
dirs.push(folder_name); // start with passed directory
do {
std::string path = dirs.top();// retrieve directory to search
dirs.pop();
if (path[path.size()-1] != '\\') // normalize the name.
path += "\\";
std::string mask = path + fmask; // create mask for searching
// traverse a directory.
if (HNULL==(finder=FindFirstFile(mask.c_str(), &file))) {
continue;
}
do {
if (!(file.dwFileAttributes & A_DIR)) // print file names
process(path, file);
} while (FindNextFile(finder, &file));
FindClose(finder);
if (HNULL==(finder=FindFirstFile((path + "*").c_str(), &file)))
continue;
do {
if ((file.dwFileAttributes & A_DIR) && (file.cFileName[0] != '.'))
dirs.push(path + file.cFileName);
} while (FindNextFile(finder, &file));
FindClose(finder);
} while (!dirs.empty());
}
int main(int argc, char **argv) {
if (argc > 2)
find_file(argv[1], argv[2]);
else
find_file("C:\\", "*");
return 0;
}