Question

The program is supposed to prompt the user for their username. Upon receiving the username it concatenates it with ‘.history’ to create username.history. Then it opens that file (username.history) and reads the input from it. I am running into a segfault here though. Whenever it opens the file, which is empty because the file doesn’t exist, it reads multiple lines and then throws the segfault. I think the problem might stem from how I’m trying to open the file, but I’m not sure. Here is the portion that is causing problems:

// File input and output
ifstream f_in;
ofstream f_out;

// Prompt user for their username.
char username[80];
cout << "Please input your username: " << endl;
cin >> username;
cout << endl;
cout << "Loading history file if it exists." << endl;

// Create file naem and initialize the file line counter to 0.
strcat(username, ".history");
int fcount = 0;

// Open file and read in lines if there are any.
// Place read lines into the command string for use later.
char tmp[50];

f_in.open(username);
while(!f_in.eof()){
    f_in >> tmp;
    cmd[fcount] = tmp;
    fcount++;
}
f_in.close();

Other pertinent info:
cmd is declared as a global variable (char cmd[200][50])

Any help will be greatly appreaciated.

Answer 1

Not sure if it is the only issue, but cmd[fcount] = tmp is wrong. You should use strcpy().