Copying one text file to another

[Gactimus]

I wrote a C++ program that is supposed to copy one text file to another.
It works fine if I specify the files to be opened and copied but when I
try to have the file names inputted by the user it doesn't work and I am
stumped. Can anyone clue me in to what I am missing?

Here is my code:


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

int main()
{
string source;
string clone;

cout << "Enter the source file: ";
cin >> source;
cout << "Enter the name of the new file: ";
cin >> clone;

ifstream in(source.c_str ); // Open for reading
ofstream out(clone.c_str ); // Open for writing
string s;
while(getline(i n, s))
out << s << "\n";

return 0;
}

[ES Kim]

Re: Copying one text file to another

"Gactimus" <gactimus@xrs.n et> wrote in message
news:1100651820 .dZSrLYW+T41iUY lgGChJng@bubban ews...[color=blue]
> I wrote a C++ program that is supposed to copy one text file to another.
> It works fine if I specify the files to be opened and copied but when I
> try to have the file names inputted by the user it doesn't work and I am
> stumped. Can anyone clue me in to what I am missing?
>
> Here is my code:
>
> ifstream in(source.c_str ); // Open for reading
> ofstream out(clone.c_str ); // Open for writing[/color]

ifstream in(source.c_str ());
ofstream out(clone.c_str ());

--
ES Kim

[Gactimus]

Re: Copying one text file to another

"ES Kim" <no@spam.mail > wrote in news:cne9gj$g83 $1@news1.kornet .net:
[color=blue]
> "Gactimus" <gactimus@xrs.n et> wrote in message
> news:1100651820 .dZSrLYW+T41iUY lgGChJng@bubban ews...
>[color=green]
>> I wrote a C++ program that is supposed to copy one text file to
>> another. It works fine if I specify the files to be opened and copied
>> but when I try to have the file names inputted by the user it doesn't
>> work and I am stumped. Can anyone clue me in to what I am missing?
>>
>> Here is my code:
>>
>> ifstream in(source.c_str ); // Open for reading
>> ofstream out(clone.c_str ); // Open for writing[/color]
>
> ifstream in(source.c_str ());
> ofstream out(clone.c_str ());[/color]

D'oh! It's always the stupid mistakes that get you. Thanks.

[Someonekicked]

Re: Copying one text file to another

a faster way would be reading all the file at once ( not looping throughout
lines), maybe it would not be a remarquable difference, anyway you can use
getline(in,s,ch ar(0));
char(0) is the null character, so the delimiter is the null character ( when
reading no more characters).


"Gactimus" <gactimus@xrs.n et> wrote in message
news:1100651820 .dZSrLYW+T41iUY lgGChJng@bubban ews...[color=blue]
>I wrote a C++ program that is supposed to copy one text file to another.
> It works fine if I specify the files to be opened and copied but when I
> try to have the file names inputted by the user it doesn't work and I am
> stumped. Can anyone clue me in to what I am missing?
>
> Here is my code:
>
>
> #include <iostream>
> #include <fstream>
> #include <cstdlib>
> #include <string>
> using namespace std;
>
> int main()
> {
> string source;
> string clone;
>
> cout << "Enter the source file: ";
> cin >> source;
> cout << "Enter the name of the new file: ";
> cin >> clone;
>
> ifstream in(source.c_str ); // Open for reading
> ofstream out(clone.c_str ); // Open for writing
> string s;
> while(getline(i n, s))
> out << s << "\n";
>
> return 0;
> }[/color]

[Gactimus]

Re: Copying one text file to another

"Someonekic ked" <someonekicked@ comcast.net> wrote in
news:JeKdnd7Tnb XcKgfcRVn-uA@comcast.com:
[color=blue]
> "Gactimus" <gactimus@xrs.n et> wrote in message
> news:1100651820 .dZSrLYW+T41iUY lgGChJng@bubban ews...
>[color=green]
>> I wrote a C++ program that is supposed to copy one text file to
>> another. It works fine if I specify the files to be opened and copied
>> but when I try to have the file names inputted by the user it doesn't
>> work and I am stumped. Can anyone clue me in to what I am missing?
>>
>> Here is my code:
>>
>>
>> #include <iostream>
>> #include <fstream>
>> #include <cstdlib>
>> #include <string>
>> using namespace std;
>>
>> int main()
>> {
>> string source;
>> string clone;
>>
>> cout << "Enter the source file: ";
>> cin >> source;
>> cout << "Enter the name of the new file: ";
>> cin >> clone;
>>
>> ifstream in(source.c_str ); // Open for reading
>> ofstream out(clone.c_str ); // Open for writing
>> string s;
>> while(getline(i n, s))
>> out << s << "\n";
>>
>> return 0;
>> }[/color]
>
> a faster way would be reading all the file at once ( not looping
> throughout lines), maybe it would not be a remarquable difference,
> anyway you can use getline(in,s,ch ar(0));
> char(0) is the null character, so the delimiter is the null character (
> when reading no more characters).[/color]

Thanks for the info. On a side note, do you know how I would go about
encrypting the file that is copied? I want to do it very simply, as in
adding 1 to every ASCII character.

[Ney André de Mello Zunino]

Re: Copying one text file to another

Gactimus wrote:
[color=blue]
> Thanks for the info. On a side note, do you know how I would go about
> encrypting the file that is copied? I want to do it very simply, as in
> adding 1 to every ASCII character.[/color]

Then read it character by character. Something like (untested):

char c;
while (source.get(c))
clone.put(c);

Hope that helps,

--
Ney André de Mello Zunino

[Ney André de Mello Zunino]

Re: Copying one text file to another

Ney André de Mello Zunino wrote:
[color=blue]
> Then read it character by character. Something like (untested):
>
> char c;
> while (source.get(c))
> clone.put(c);[/color]

Of course, you can add '1' or do whatever you like with the character
before you write it to the output file stream.

--
Ney André de Mello Zunino

[Gactimus]

Re: Copying one text file to another

Ney André de Mello Zunino <zunino@inf.ufs c.br> wrote in
news:2vvsu9F2pn plmU2@uni-berlin.de:
[color=blue]
> Ney André de Mello Zunino wrote:
>[color=green]
>> Then read it character by character. Something like (untested):
>>
>> char c;
>> while (source.get(c))
>> clone.put(c);[/color]
>
> Of course, you can add '1' or do whatever you like with the character
> before you write it to the output file stream.[/color]

Thanks. I'll try it out.

[Gactimus]

Re: Copying one text file to another

Ney André de Mello Zunino <zunino@inf.ufs c.br> wrote in news:2vvsu9F2pn plmU2@uni-berlin.de:
[color=blue]
> Ney André de Mello Zunino wrote:
>[color=green]
>> Then read it character by character. Something like (untested):
>>
>> char c;
>> while (source.get(c))
>> clone.put(c);[/color]
>
> Of course, you can add '1' or do whatever you like with the character
> before you write it to the output file stream.[/color]

Ney André de Mello Zunino <zunino@inf.ufs c.br> wrote in news:2vvsu9F2pn plmU2@uni-berlin.de:
[color=blue]
> Ney André de Mello Zunino wrote:
>[color=green]
>> Then read it character by character. Something like (untested):
>>
>> char c;
>> while (source.get(c))
>> clone.put(c);[/color]
>
> Of course, you can add '1' or do whatever you like with the character
> before you write it to the output file stream.[/color]

It put the code in the program but I get an error:

error C2039: 'get' : is not a member of 'basic_string<c har,struct std::char_trait s<char>,class std::allocator< char> >'

Any ideas? Maybe I just don't know how to implement your code.

[John Harrison]

Re: Copying one text file to another


"Gactimus" <gactimus@xrs.n et> wrote in message
news:7Fzmd.34$O c.1@tornado.tam pabay.rr.com...[color=blue]
> Ney André de Mello Zunino <zunino@inf.ufs c.br> wrote in
> news:2vvsu9F2pn plmU2@uni-berlin.de:
>[color=green]
>> Ney André de Mello Zunino wrote:
>>[color=darkred]
>>> Then read it character by character. Something like (untested):
>>>
>>> char c;
>>> while (source.get(c))
>>> clone.put(c);[/color]
>>
>> Of course, you can add '1' or do whatever you like with the character
>> before you write it to the output file stream.[/color]
>
> Ney André de Mello Zunino <zunino@inf.ufs c.br> wrote in
> news:2vvsu9F2pn plmU2@uni-berlin.de:
>[color=green]
>> Ney André de Mello Zunino wrote:
>>[color=darkred]
>>> Then read it character by character. Something like (untested):
>>>
>>> char c;
>>> while (source.get(c))
>>> clone.put(c);[/color]
>>
>> Of course, you can add '1' or do whatever you like with the character
>> before you write it to the output file stream.[/color]
>
> It put the code in the program but I get an error:
>
> error C2039: 'get' : is not a member of 'basic_string<c har,struct
> std::char_trait s<char>,class std::allocator< char> >'
>
> Any ideas? Maybe I just don't know how to implement your code.[/color]

source and clone are not strings, they are the file streams. What you called
in and out in your original code.

Incidentally I would not use the method that Someonekicked recommended, it
does not work if your file contains a null byte. Nor would I use the method
you had originally because that adds an extra newline when the original file
does not end in a newline. Reading and writing one character at a time as
Andre recommended is the simplest.

john

[Karl Heinz Buchegger]

Re: Copying one text file to another

Gactimus wrote:[color=blue]
>[color=green]
> >[color=darkred]
> >> Then read it character by character. Something like (untested):
> >>
> >> char c;
> >> while (source.get(c))
> >> clone.put(c);[/color]
> >
> > Of course, you can add '1' or do whatever you like with the character
> > before you write it to the output file stream.[/color]
>
> It put the code in the program but I get an error:
>
> error C2039: 'get' : is not a member of 'basic_string<c har,struct std::char_trait s<char>,class std::allocator< char> >'
>
> Any ideas? Maybe I just don't know how to implement your code.[/color]


Look at the error message. What does it talk about?

It talks about basic_string. Hmm. basic_string. That has something
to do with string! It says that 'get' is not a member of some string
class. But why string? get is something you want to apply to a stream
not a string. So chances are high that you used the wrong variable and
applied get to it. You want to get from the stream and not the string.

I know. Those error messages are cryptic and sometimes even
misleading. But you definitly *must* learn to read them and
draw your conclusions from them.


--
Karl Heinz Buchegger
kbuchegg@gascad .at

[Francis Glassborow]

Re: Copying one text file to another

In article <2vvsraF2pnplmU 1@uni-berlin.de>, Ney André de Mello Zunino
<zunino@inf.ufs c.br> writes[color=blue]
>Gactimus wrote:
>[color=green]
>> Thanks for the info. On a side note, do you know how I would go about
>> encrypting the file that is copied? I want to do it very simply, as in
>> adding 1 to every ASCII character.[/color]
>
>Then read it character by character. Something like (untested):
>
>char c;
>while (source.get(c))
> clone.put(c);
>
>Hope that helps,[/color]

Actually there is a subtle problem waiting to bite if you open the files
in text mode; sometimes the encryption mechanism will generate a control
character which will cause problems with reading the encrypted file. It
is, therefore, much safer when encrypting/decrypting a file to open the
file in binary mode.


--
Francis Glassborow ACCU
Author of 'You Can Do It!' see http://www.spellen.org/youcandoit
For project ideas and contributions: http://www.spellen.org/youcandoit/projects

[Chris \( Val \)]

Re: Copying one text file to another


"Gactimus" <gactimus@xrs.n et> wrote in message
news:7Fzmd.34$O c.1@tornado.tam pabay.rr.com...
| Ney André de Mello Zunino <zunino@inf.ufs c.br> wrote in
news:2vvsu9F2pn plmU2@uni-berlin.de:
|
| > Ney André de Mello Zunino wrote:
| >
| >> Then read it character by character. Something like (untested):
| >>
| >> char c;
| >> while (source.get(c))
| >> clone.put(c);
| >
| > Of course, you can add '1' or do whatever you like with the character
| > before you write it to the output file stream.
|
| Ney André de Mello Zunino <zunino@inf.ufs c.br> wrote in
news:2vvsu9F2pn plmU2@uni-berlin.de:
|
| > Ney André de Mello Zunino wrote:
| >
| >> Then read it character by character. Something like (untested):
| >>
| >> char c;
| >> while (source.get(c))
| >> clone.put(c);
| >
| > Of course, you can add '1' or do whatever you like with the character
| > before you write it to the output file stream.
|
| It put the code in the program but I get an error:
|
| error C2039: 'get' : is not a member of 'basic_string<c har,struct
std::char_trait s<char>,class std::allocator< char> >'
|
| Any ideas? Maybe I just don't know how to implement your code.

One method I can think of to copy a file is to open
the file in binary mode, and use the 'rdbuf()' member:

out << in.rdbuf();

Cheers.
Chris Val