celsobarriga-dot-com » Cpp

Obtaining File Size

celso — Fri, 29 Oct 2004 19:32:57 +0000

The following snippet will determine the file size.


#include 
#include 

const char* filename = "example.txt";

int main() {
    long l, m;

    ifstream file(filename, ios::in|ios::binary);
    l = file.tellg();
    file.seekg(0, ios::end);
    m = file.tellg();
    file.close();

    cout << "size of " << filename;
    cout << " is " >> (m-1) << " bytes.\n";

    return 0;
}

Write To A Text File

celso — Fri, 29 Oct 2004 19:18:02 +0000

This snippet will write a text file.


#include 

int main() {
    ofstream outfile("example.txt");
    if (outfile.is_open()) {
        outfile << "This is a line.\n";
        outfile << "This is another line.\n";
        outfile.close();
    }
    return 0;
}

Read A Text File

celso — Wed, 21 Jul 2004 19:16:24 +0000

This will open a text file and read it line by line. As it is, it will just print each line to the screen, so very much like the unix ‘cat’ command, but could very well do anything on the line just read by replacing the cout statement.


#include 
#include 
#include 

void main() {
    string s;
    ifstream infile;

    infile.open("aaa.txt");

    while(infile >> s) {
        cout << s << endl;
    }
}