Swap characters in a file.
#include <iostream> #include <fstream> using namespace std; int main(int argc, char *argv[]) { if(argc!=2) { cout << "usage: SWAP <filename>\n"; return 1; } // open file for input/output fstream io(argv[1], ios::in | ios::out | ios::binary); if(!io) { cout << "Cannot open file.\n"; return 1; } char ch1, ch2; long i; for(i = 0 ; !io.eof(); i+=2) { io.seekg(i, ios::beg); io.get(ch1); if(io.eof()) continue; io.get(ch2); if(io.eof()) continue; io.seekg(i, ios::beg); io.put(ch2); io.put(ch1); } io.close(); return 0; }