running processes as a user

[Anon]

I want to execute a process as if I am looged in as specific user. By default the scripts run as user "nobody" . . . and I don't have the privileges I want. Is there something like (for example)

system_as_user("username", "password", "commandline");

or any other way to do this ?
Thanks

[[deleted]]

read about sudo.

note: this is very very dangerous/don't do it unless you know what you are doing