I have a (very big) csv-file with following format:

```
id;surname;firstname;aliases
1;Simpson;Homer;Homer Jay Simpson,Homer J. Simpson
2;Simpson;Bart;Bartholomew JoJo Simpson,Bartholomew Simpson
3;Krusty the Clown;;Herschel Shmoikel Pinchas Yerucham Krustofsky
4;Simpson;Lisa;

```

Now I want to transform that into following format:

```
id;name
1;Homer Simpson
1_1;Homer Jay Simpson
1_2;Homer J. Simpson
2;Bart Simpson
2_1;Bartholomew JoJo Simpson
2_2;Bartholomew Simpson
3;Krusty the Clown
3_1;Herschel Shmoikel Pinchas Yerucham Krustofsky
4;Lisa Simpson

```

For performance reasons I would like to do that with `awk` or another UNIX-command line tool.

With `awk -F ';' '{print $1, $3, $2}'` I can separate the semicolon separated line. But how do I use `awk` in `awk` for splitting the comma separated entry again?