function that returns a string...

[Nelphin]

i would like to have a function (actually my first one) that returns me a string.

i have some really basic questions:

1.) i know my resulting string will be 80 letters long. so the box i put it in must be 81? for the end of string thing?
2.) would this be the apropriate way to declare such a function: or is there something better than char*
char* extractheaderstring(); ?
3.) lets say my string contains backslashes since its from a text file or whatever and i have no control what it contains, how do i deal with this, so i can cout the string without triggering magic backslash commands automatically?

[Gaminic]

Use C++ strings instead:
http://www.cplusplus.com/reference/string/string/

Much easier to use and less chance on errors!

[Nelphin]

ok i created something with string now, but im not happy yet... this surely goes easier?

{
    string buffer;
    char* charbuff;
    for (int i = 0; i<80; i++) { // since i want 80 letters in my string
    FileBin.seekp(i);
    FileBin.read(charbuff,1);
    buffer.append(charbuff);
    }
    cout <<"buffer is: "<< buffer; //checking content of buffer now...
}

see screenshot for result:

http://screencast.com/t/llwnjirb9m80

[Nelphin]

fstream FileBin("S:\\Coding\\codeblocks\\spielereien\\20110927_001\\settingup\\datei2.dat", ios::in|ios::out|ios::binary); //?
if (FileBin.is_open())
{
    char* buffer;
    FileBin.getline(buffer,80);
    cout <<"buffer is: "<< buffer;
}

trying to make the code better with getline but it causes an error that i dont understand:

see screenshot:

http://screencast.com/t/LAKSQMAsPY

[Disch]

char*s are not strings! They're pointers, and they don't mean anything unless you actually have them point to something.

Save yourself a ton of headaches and forget about char*. Just use strings.

// get rid of this crap
//    char* buffer;
//    FileBin.getline(buffer,80);

// replace it with this:
    string str;
    getline(FileBin,str);

[Nelphin]

thanks for trying to help :)

remember im a total newbie and yes i would love to see a "good" way to do what i want to have.

but unfortunatly your code does not work at all,

it tells me getline is unknown name

here is the code i tried out after your posting:

fstream FileBin("S:\\Coding\\codeblocks\\spielereien\\20110927_001\\settingup\\datei2.dat", ios::in|ios::out|ios::binary); //?
if (FileBin.is_open())
{
	string str;
    getline(FileBin,str);
    cout <<"buffer is: "<< str;

}

as you can see i replaced my crap with your two lines

[Disch]

it tells me getline is unknown name

Try adding <iostream> to your #includes.


EDIT: but you must have iostream included if you're using cout....

that error makes no sense. Can you post the actual error you're getting? (the whole thing -- don't paraphrase/summarize)

[Nelphin]

http://screencast.com/t/9cWwEjEWs1R

hope it helps - its german :(

[zb0S216C]

You need to include <string> in-order for std::cout to understand how to handle a std::string object.

Just to clarify:

1) "String" isn't a string.
2) "String\0" is a string.
3) char* is a pointer to a character. It's not a string.
4) char *String = "String\0" is a pointer to a string literal.

_Wazzak

[Nelphin]

ok the string include worked wonders... i didnt have it included because microsoft visual c++ 2010 "auto corrected" #include <string> to #include <specstrings.h>

now the code "magically" works but i have not really understood why and how.

i am reading a file bytewise, because it is not a .txt file. i know from the file only that the first 80 byte are unsinged chars.

i want them in a string.

getline "seems" to do the magic.
but what tells getline that it has to read 80 chars? and what must i do if i only want 40? or 10? or 200?

thanks!

[Nelphin]

im really desperate to understand that, can someone help?

how or what tells getline to get 80 unsigned chars from the unknown file and put them in a string?