sourceing for different shells;
thats 'dot space path_to_env_file' where your env file is either .profile, .kshrc, or .bashrc(or .bash_profile)
thats 'source path_to_env_file' where your env file is either .cshrc or .tcshrc
all the above env files would normaly be found in your home directory for your user.
Lastly, logging your user out and back in will achieve the same results.
Originally posted by stickman
You don't have to reboot just because your changed your PATH or modified your .profile. You can simply re-source your .profile.