list maps (from harddrive folder)
Author
Hi
I have a mapfolder and must be able from my game to list all available *.map files. And i dont really know how to achieve this...
Thanks
Erik
What language?
What operating system?
Directory manipulation is typically a platform-dependent operation.
What operating system?
Directory manipulation is typically a platform-dependent operation.
Look up boost::filesystem. There's no *standard* way to do this because C++ doesn't know you have a map folder - and you can't tell it you do - because it doesn't know what a folder is. (This is so that C++ compilers can exist for hardware that doesn't normally even have an operating system installed on it.)
Author
oh ok.
i use c++ on windows32. I can save and load maps using strings like "mymap.map" (i use fread fwrite for this purpose). I just dont know how to find files if i dont know the exact file name. (to have the player look in the folder and write the name himself isnt really optimal but the only thing i know at the moment.
Erik
i use c++ on windows32. I can save and load maps using strings like "mymap.map" (i use fread fwrite for this purpose). I just dont know how to find files if i dont know the exact file name. (to have the player look in the folder and write the name himself isnt really optimal but the only thing i know at the moment.
Erik
FindFirstFile and FindNextFile are the Win32 API calls you are looking for.
Alternatively your compiler will possibly have a non-standard header, commonly called something like <dir.h> that will offer some compiler-dependant calls for this purpose, but they probably just wrap the calls above.
Also, I have to ask, if you are using C++, why are you using fwrite and fread rather than std::fstreams?
Alternatively your compiler will possibly have a non-standard header, commonly called something like <dir.h> that will offer some compiler-dependant calls for this purpose, but they probably just wrap the calls above.
Also, I have to ask, if you are using C++, why are you using fwrite and fread rather than std::fstreams?
Author
hmm its just my habit. i havnt checked that one up. Is it easier to use?
(i use ms visual c++ to compile)
(i use ms visual c++ to compile)
Not just easier - safer.
The only slight complication, if that is the word, is that fstream::read expects a char* pointer rather than a void* pointer for the buffer it is writing to, so if you are trying to read into an int for example, you have to do
The other chief advantage of using streams is when you are not reading or writing binary data, but text. In the same way that fprintf works the same as printf, a text ofstream works the same way as cout.
Unlike the C stuff though, since they inherit from the same base you can do stuff like this:
#include <cstdio>#include <fstream>using namespace std;bool cstyle(){ char buf[32]; FILE *fp=fopen("test.txt","rb"); if(!fp) return false; fread(buf,sizeof(char),32,fp); CallAFunctionThatThrowsException(); // oops - file not flushed and closed if(TestData(buf)==false) return false; // oops - file not flushed and closed fclose(fp); return true;}bool cppstyle(){ char buf[32]; ifstream is("test.txt",ios::binary); if(!is.is_open()) return false; is.read(buf,32); CallAFunctionThatThrowsException(); // no problem - file closed properly if(TestData(buf)==false) return false; // no problem - file closed properly return true;}The only slight complication, if that is the word, is that fstream::read expects a char* pointer rather than a void* pointer for the buffer it is writing to, so if you are trying to read into an int for example, you have to do
int i;is.read((char*)&i,sizeof(int));The other chief advantage of using streams is when you are not reading or writing binary data, but text. In the same way that fprintf works the same as printf, a text ofstream works the same way as cout.
Unlike the C stuff though, since they inherit from the same base you can do stuff like this:
#include <iostream>#include <fstream>#include <string>using namespace std;void out(ostream &os,const string &text){ os << text << endl;}int main(){ out(cout,"hello"); // prints to screen ofstream os("dump.txt"); out(os,"hello"); // same function now prints to file}
Author
HANDLE hFind;
1) hFind= FindFirstFile("data/maps/*.map",0);
2) hFind= FindFirstFile("data/maps/",0);
3) hFind= FindFirstFile("data/maps/1.map",0);
1)access violation crash
2)no file found
3)access violation crash (the specified file exists)
What am i doing wrong?
Thanks
Erik
1) hFind= FindFirstFile("data/maps/*.map",0);
2) hFind= FindFirstFile("data/maps/",0);
3) hFind= FindFirstFile("data/maps/1.map",0);
1)access violation crash
2)no file found
3)access violation crash (the specified file exists)
What am i doing wrong?
Thanks
Erik
You can't pass 0 as the second argument. You have to pass the address of a WIN32_FIND_DATA structure that recieves information about the file:
If you want to keep searching, you then call bool FindNextFile(hFind,&Data) which returns false when it can't find any more files.
The link I provided above goes into a lot more detail about these functions that I have.
void f(){ WIN32_FIND_DATA Data; HANDLE hFind; hFind = FindFirstFile("*.txt", &Data); if(hFind!=INVALID_HANDLE_VALUE) { cout << Data.cFileName << endl; // found file name FindClose(hFind); }}If you want to keep searching, you then call bool FindNextFile(hFind,&Data) which returns false when it can't find any more files.
The link I provided above goes into a lot more detail about these functions that I have.
Author
thanks it works now!
this really steps my app up a bit from totally temporary sollution.
Erik
this really steps my app up a bit from totally temporary sollution.
Erik
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