Create file and save it as current logged in username.txt using C programming

Question

I want to create a file with C and save it as the current logged in "username".txt

For example: if the current user is bob, when the runs the program it create a file named "bob.txt" under "c:\users\bob\MAP\" directory

The code I have below saves a file data.txt under "c:\users\bob\MAP\" directory. However i want to make the saved file as "bob.txt" given that he is the current logged in user executing the program.

char oBuffer[MAX_PATH];
memset(oBuffer, 0, MAX_PATH);
ExpandEnvironmentStrings("%userprofile%", oBuffer, MAX_PATH);
strcat(oBuffer, "\\MAP\\");
CreateDirectoryA(oBuffer, 0);
strcat(oBuffer, "data.dat");
strcpy(LOG_PATH, oBuffer); 

logfile = fopen(("%s.dat", getenv("USERPROFILE")), "a+");

I would like to have "c:\users\bob\MAP\bob.txt" create on execution of the program.

Thanks in advance

Answer 1

just use the name already copied to oBuffer

// ... UNTESTED CODE
ExpandEnvironmentStrings("%userprofile%", oBuffer, MAX_PATH);
// assume "C:\Users\username"
//         0123456789 username starts at position 9
int userpos = 9; // TODO: better user strrchr()
int uplen = strlen(oBuffer); // username ends at the end of the string
strcat(oBuffer, "\\MAP\\"); // oBuffer now has "C:\Users\username\MAP\"
CreateDirectoryA(oBuffer, 0);
//strcat(oBuffer, "data.dat");
sprintf(oBuffer, "%s%.*s.txt", oBuffer, uplen - userpos, oBuffer + userpos);
// oBuffer now has "C:\Users\username\MAP\username.txt"
// ...