appending to a file

This should be easy to answer.
I have a file with many lines of numbers
ie: 3+4/8
8-(5+3)
....
Anyway, I need to add the $ character to the end of each line. I forgot how to do this however. I was trying to do a search for a new line and then insert, but I forgot if when doing a while loop to check if it tries to add the character afterwards...Take a look at my code and give any suggestions.

Thanks

Code:

---

#include <iostream>
#include <fstream>
using namespace std;
ifstream infile;
ofstream outfile;

int main()
{
char tok;
infile.open("data.dat");
infile >> tok;
while (!infile.eof())
{
  while(tok='\n')
  {
    outfile << '$';
    infile >> tok;
  }

}

return 0;
}

---

Code:

---

while(tok='\n')

---

should be

Code:

---

while(tok=='\n')

---

Also, you never opened an output file, and even if you had, you aren't ever actually outputting the token, you are only outputting the '$'. Your output file would just be:

$$$$$$$$$$$$$$$$$$$$$$$$

Try fixing those problems first and then see if you can figure out the rest.

Okay, I have decided to create a new file to copy the data to along with the end tolkien. It copies the data without the endlines which makes me believe I might need to use getline(). It still doesn't add the end tolkiens obivously. I'll look through some old notes to see.

Here is my new code:

Code:

---

#include <iostream>
#include <fstream>
using namespace std;
ifstream infile;
ofstream outfile;

int main()
{
char tok;
infile.open("infix.dat");
outfile.open("infix2.dat");
infile>>tok;
while(!infile.eof())
{
  outfile<<tok;
  if(tok=='\n')
  {
    outfile << '$';
  }
infile>>tok;
}

---

You're right. You will have to use getline. I totally forgot that >> skips whitespace, even going one char at a time.

Of course, getline is probably easier, since you don't have to check for the newline anymore. Your code looks fine to me except for that one problem.

okay, hopefully this will be my last post .. I got it to work the way I wanted but one last thing. I need to edit the file I am writing to right after I write to it.
I tried this new code jsut to test to see if it works, but it says it won't read from the file.
Here is the code:

Code:

---

#include <iostream>
#include <fstream>
using namespace std;
ifstream infile;
ofstream outfile;

int main()
{
char tok;
infile.open("infix.dat");
outfile.open("infix2.dat");
infile.get(tok);
while(!infile.eof())
{
  outfile<<tok;
  if(tok=='\n')
  {
    outfile << '$';
  }
infile.get(tok);
}

infile.open("infix2.dat");
if(infile.fail())
{cout << "error";
return false;}
else
cout << "Please work"<<endl;
return 0;
}

---

Don't forget to close the output file when you are done writing to it, and the input file while you're at it.

tried that.. still gives me "error"

Code:

---

#include <iostream>
#include <fstream>
using namespace std;
ifstream infile;
ofstream outfile;

int main()
{
char tok;
infile.open("infix.dat");
outfile.open("infix2.dat");
infile.get(tok);
while(!infile.eof())
{
  outfile<<tok;
  if(tok=='\n')
  {
    outfile << '$';
  }
infile.get(tok);
}
infile.close();
outfile.close();


infile.open("infix2.dat");
if(infile.fail())
{cout << "error";
return false;}
else
cout << "bite me"<<endl;
return 0;
}

---

Anyone have any idea on this last problem. It is the last thing I am stuck on.

Thanks

Try this one

Code:

---

infile.close();
outfile.close();

infile.clear();    // reset the stream
infile.open("infix2.dat");

---

awesome, thanks... i forgot about that fxn