Hi , I am trying to create a loop to call in the entries from the text file named Set. The entries of Set.txtare : 1 2 3 2 4 5 and so on .. (64 such combinations)[/code] it basically means the first combination for testing is 1 2 3 and next has to be 2 4 5 and so i have 64 such entries defined in set my test files are located in D://data// and are named tst_data1 to tst_data64. i created a loop for test set but its incorrect Code: // loop for test samples char basefilename[] = "D://data//"; char , testFilen[160], numiChar[10]; for (int i=1; i<=64; i++) { strcpy(basefilenme, "D://data//"); strcat(testfilename, Set[]); if (testfilenme[i]=='_' && testfilenme[i+1]=='\0'){ strcat(testfilename, numiChar); strcat(testfilename, "_"); break; } strcat(testfilename, ".txt"); cout<<testfilename<<endl; please let me know how can i call the Set .txt and how to define it. thanks in advance!