UNIX for Dummies Questions & Answers

I have a very elementary question that is kind of buggin me because I cannot figure it out.

1. How do you make a new group, give it a name, and assign permissions to specific users to access this group?

2. How do you delete a file that begins with a '-'?

3. How do you login as a different user within the same terminal in UNIX (obviously without completely logging out and re-logging in as the different user)?

Any kind of help is appreciated

1) if you are on a solaris box you can just use the command groupadd. if you dont have groupadd you can just add it to the file /etc/group. the format will be something like this:

root::0:john, where root is the group name, 0 is the GID (group ID) and john is a user in the group root. you can add more users separated by commas. e.g. root::0:john,mike,jennifer

2) to delete a file that starts with a '-', or any other special character, just do rm ./-filename. to do this you have to be in the same directory as the file. or if you are in let's say /etc and the file is in /root and the filename is '-file' . you would do this: rm /root/-file .

3) to login as a different user, use the command su (switch user) username. e.g. 'su john'. to have john's preferences you would use 'su - john'. if you just type su it will ask you for the root password, because root is the default username for the su command.