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Evil ifstream!

Started by Xtremehobo Sep 6, 2003 at 5:29 PM 5 replies 450+ views

Original Post

Xtremehobo

263

Xtremehobo

Sep 6, 2003 at 5:29 PM

My ifstream object quits reading characters from a file into my buffer when it hits a TAB (0x9) character.

	ifstream fin;
	fin.open(filename);
	char buffer[2048];
	fin >> buffer;
	fin.close();
	MessageBox(NULL,buffer,"test",MB_OK);

the text document it''s trying to open looks like this:

matt	mypass	sysadmin
nick	hispass	guest

My MessageBox just prints out "matt" and that''s it. Any ideas? thanks. ----- Everyone but me has an interesting sig

Thunder_Hawk

Sep 6, 2003 at 5:37 PM

Use binary mode. A tab is considered whitespace. It''s the default behavior of an istream to stop reading at whitespace when using the extraction (>>) operator.

______________________________________________________________
The Phoenix shall arise from the ashes... ThunderHawk -- ¦þ
MySite
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Thunder_Hawk

Sep 6, 2003 at 5:48 PM


	ifstream fin(filename, ios::binary);
	ostringstream iss;
	iss << fin.rdbuf();
	fin.close();
	MessageBox(NULL,iss.str().c_str(),"test",MB_OK);

That should work (although I can't remember if binary mode is necessary here for some odd reason).

______________________________________________________________
The Phoenix shall arise from the ashes... ThunderHawk -- ¦þ
MySite
______________________________________________________________

[edited by - Thunder_Hawk on September 6, 2003 6:48:58 PM]

C-Junkie

139

C-Junkie

Sep 6, 2003 at 6:11 PM

nope, not binary mode. (miniRANT: BINARY MODE ONLY DOES \r\n and \n TRANSLATION AND ONLY ON WINDOWS! (insert rare exceptions here))

OP, you want to read() the data, not extract>> it. the extraction operator for char[] and strings only reads up to whitespace. you want to read all of it.

Xtremehobo

Author

263

Xtremehobo

Sep 7, 2003 at 12:42 AM

ok, I''m using read and it''s working how I want it now. Thanks

sjelkjd

120

sjelkjd

Sep 7, 2003 at 3:42 PM


ifstream fin(filename);
istreambuf_iterator begin(fin),end;
string buffer(begin,end);

Don''t use fixed size buffers!

Seriema

Sep 7, 2003 at 4:01 PM

Effective STL by Scott Meyers
Item 29 - "Consider istreambuf_iterators for character-by-character input."


std::ifstream inputFile(filename);
std::string fileData(std::istreambuf_iterator<char>(in), std::istreambuf_iterator<char>());

and there you have it...

But I think there's a way to stop streams from stopping at white spaces... just looked at http://www.cplusplus.com/ref/iostream/ and found this: ios_base::skipws and ios_base::flags(). So if my assumtions are correct then inputFile.flags( ios_base::skipws ); will make the stream skip whitespaces and read the whole thing with one >> extraction? anyway... you seem to have found what you wanted so it doesn't matter anyway

"No lies of sugar can sweeten the sournes of reality"

}+TITANIUM+{ A.K.A. DXnewbie[onMIRC]

[edited by - Seriema on September 7, 2003 5:09:22 PM]

[edited by - Seriema on September 7, 2003 5:09:41 PM]

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