Run part of a bash script as a different user

Question

Is there a way to make part of a script run as a different (non-root) user? If it helps , the part to be run as a different user occurs at the end of the script

Edit :
OS -> Ubuntu 9.04

Answer 1

Use the sudo command in the script.

In the form:

sudo -u _username_ _command_

the sudo command runs command as the user username.

If the script is being run as root, I don't think it will prompt for a password. Otherwise, this article discusses how to use sudo with password in one command line?, and this article discusses how to use sudo without password?

Answer 2

EricJLN's answer is good, but the serverfault advice is slightly dangerous - would allow anyone to run anything as root! So I'm posting here because I can't format the comment.

I would recommend using visudo to give the permissions you need as precisely as you can. Type visudo and add a line like:

username hostname = NOPASSWD: /full/path/to/command1, full/path/to/command2

If you do need to run this same thing on many hosts, you could open it up with:

username ALL = NOPASSWD: /full/path/to/command1, full/path/to/command2

But I would *not use either:

username ALL=(ALL) NOPASSWD: ALL

or username hostname = ALL

The sudoer man page has lots of gory details

Answer 3

not so sure about it, but if you want that ONLY the end of that script will run as a different user, you could add su someuser before the end of the script.

Am I missing something?

Hope that helps,

Regards