Reload bash's .profile without logging out and back in again
Solution 1:
This should work for the current terminal:
. ~/.profile
. is a bash builtin and a synonym for source, see man bash:
. filename [arguments]
source filename [arguments]
Read and execute commands from filename in the current shell environment (…).
Solution 2:
If you don't want to start a new shell but execute the script in the current shell, you source it:
source script_name.sh
source = .
The Bash source built-in is a synonym for the Bourne shell . (dot) command.
courtesy - tldp.org