Write to a file from a C++ ROS node?

edit

I just tried your example code but changed it to:

#include <fstream>
using namespace std;
.
.
.
ofstream myfile("example.txt", ios::out | ios::binary);
myfile << "Writing this to a file.\n";
myfile.close();

Edit: Cleaning up thanks to @joq's comment.

Using rosrun this created and wrote to "example.txt" in the directory that I ran the node from. I tried running from several different directories, and each time the file "example.txt" showed up in the directory I was in, and had nothing to do with the location of the node binary.

Using roslaunch this created and wrote "example.txt" in ~/.ros no matter which directory I run the roslaunch command from.

void insert_node(char* name,int roll_no ,char* sems,char* major,float gpa) { fstream myfile; myfile.open("myfile.txt", ios::out|ios::binary|ios::app); Node* newptr = new Node(/name,roll_no,sems,major,gpa/); if(firstptr==NULL && lastptr==NULL) { firstptr = newptr; lastptr = newptr; } else if((newptr->getname()>firstptr->getname())&&(newptr->getname()>lastptr->getname())) { lastptr->nextptr = newptr; newptr->nextptr = NULL; lastptr = newptr; } else if(newptr->getname()<firstptr->getname()) { newptr->nextptr = firstptr; firstptr = newptr; } else { Node* tempptr; tempptr = firstptr; while(newptr->getname()> tempptr->nextptr->getname()) { tempptr = tempptr->nextptr; } newptr->nextptr = tempptr->nextptr; tempptr->nextptr = newptr; }

                   myfile.write((Node*)&newptr, sizeof(newptr)); //i have error on thiis line but if i put char* instead of Node* then i got a different type of output in my file plzz anyone help me.. :(

                   myfile.close();
                  }