Programming Forums > Application Development > C++

Ancient Dragon · Jun 13th, 2005, 3:06 PM

my VC++ 6.0 MFC program is compiled for UNICODE. I have a std::wstring object that contains a filename. I tried to use wifstream in(filename.c_str()) but got error that the compiler can't convert the first parameter from wchar_t* to char*. Is there another way to do it without explicitly converting it myself? If not, how do people using other languages use anything from the fstream STL library, or is the C-style FILE the only way?

Thanks

Scorpions4ever · Jun 13th, 2005, 5:50 PM

Darn site keeps going up and down. Anyway, one way to do this is to convert the filename to type string like this:

(Toggle Plain Text)

#include <string>
#include <fstream>
#include <iostream>
using namespace std;

int main(void) {
  wstring filename = L"string.cpp";
  string s_filename(filename.begin(), filename.end());
  wifstream in(s_filename.c_str());
  wstring line;
  while (!in.eof()) {
    getline(in, line);
    wcout << line << endl;
  }
  in.close();
  return 0;
}

Ancient Dragon · Jun 13th, 2005, 5:53 PM

I don't want to convert to ascii -- what if the filename is Chinese or Japanese, or some other language that doesn't fit in ascii???

Scorpions4ever · Jun 13th, 2005, 6:03 PM

BTW, I forgot to mention that the solution above is not necessarily portable either. Also, if the filename is something in japanese or whatever, wifstream fails. Several people have proposed fixes to the STL library for this. Apparently, one of the things holding this up is that several filesystems don't actually support unicode.

Scorpions4ever · Jun 13th, 2005, 6:04 PM

BTW dinkumware (the guys that Microsoft uses for their STL implementation) apparently has a lib that supports wifstream with a wchar_t * filename.

Ancient Dragon · Jun 13th, 2005, 7:34 PM

well, thanks for the comments. Not what I wanted to hear, so I guess I'll have to use wfopen() and associated functions.

Not supporting UNICODE is a lousy excuse for not fixing wifstream() -- there are a lot of other STL unicode classes too, such as wstring that don't work on os without unicode support.

Quote:

Originally Posted by uman

Does WIndows even allow wide-character filenames?

Windows is not the only os that support UNICODE -- *nix and others do too.

uman · Jun 13th, 2005, 6:01 PM

Does WIndows even allow wide-character filenames?

Jun 13th, 2005, 3:06 PM	#1
Ancient Dragon PFO God In Training Join Date: Jun 2005 Location: near St Louis, MO. (USA) Posts: 599 Rep Power: 4	UNICODE and ifstreams my VC++ 6.0 MFC program is compiled for UNICODE. I have a std::wstring object that contains a filename. I tried to use wifstream in(filename.c_str()) but got error that the compiler can't convert the first parameter from wchar_t* to char*. Is there another way to do it without explicitly converting it myself? If not, how do people using other languages use anything from the fstream STL library, or is the C-style FILE the only way? Thanks

Jun 13th, 2005, 5:50 PM	#2
Scorpions4ever Programmer Join Date: Jun 2005 Posts: 86 Rep Power: 4	Darn site keeps going up and down. Anyway, one way to do this is to convert the filename to type string like this: (Toggle Plain Text) #include <string> #include <fstream> #include <iostream> using namespace std; int main(void) { wstring filename = L"string.cpp"; string s_filename(filename.begin(), filename.end()); wifstream in(s_filename.c_str()); wstring line; while (!in.eof()) { getline(in, line); wcout << line << endl; } in.close(); return 0; } #include <string> #include <fstream> #include <iostream> using namespace std; int main(void) { wstring filename = L"string.cpp"; string s_filename(filename.begin(), filename.end()); wifstream in(s_filename.c_str()); wstring line; while (!in.eof()) { getline(in, line); wcout << line << endl; } in.close(); return 0; }

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

Jun 13th, 2005, 5:53 PM	#3
Ancient Dragon PFO God In Training Join Date: Jun 2005 Location: near St Louis, MO. (USA) Posts: 599 Rep Power: 4	I don't want to convert to ascii -- what if the filename is Chinese or Japanese, or some other language that doesn't fit in ascii???

Jun 13th, 2005, 6:03 PM	#4
Scorpions4ever Programmer Join Date: Jun 2005 Posts: 86 Rep Power: 4	BTW, I forgot to mention that the solution above is not necessarily portable either. Also, if the filename is something in japanese or whatever, wifstream fails. Several people have proposed fixes to the STL library for this. Apparently, one of the things holding this up is that several filesystems don't actually support unicode.

Jun 13th, 2005, 6:04 PM	#5
Scorpions4ever Programmer Join Date: Jun 2005 Posts: 86 Rep Power: 4	BTW dinkumware (the guys that Microsoft uses for their STL implementation) apparently has a lib that supports wifstream with a wchar_t * filename.

Jun 13th, 2005, 6:01 PM	#7
uman Expert Programmer Join Date: Dec 2004 Posts: 794 Rep Power: 4	Does WIndows even allow wide-character filenames?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Programming Forums > Application Development > C++

UNICODE and ifstreams