How to reload .bashrc settings without logging out and back in again?

You can enter the long form command:

source ~/.bashrc

or you can use the shorter version of the command:

. ~/.bashrc

Or you could use:

exec bash

This does the same thing, and is easier to remember (at least for me).

The exec command completely replaces the shell process by running the specified command-line. In our example, it replaces whatever the current shell is with a fresh instance of bash (with the updated configuration files).

To complement and contrast the two most popular answers, . ~/.bashrc and exec bash:

Both solutions effectively reload ~/.bashrc, but there are differences:

. ~/.bashrc or source ~/.bashrc will preserve your current shell session: Except for the modifications that reloading ~/.bashrc into the current shell (sourcing) makes, the current shell process and its state are preserved, which includes environment variables, shell variables, shell options, shell functions, and command history.

Except for the modifications that reloading ~/.bashrc into the current shell (sourcing) makes, the current shell process and its state are preserved, which includes environment variables, shell variables, shell options, shell functions, and command history.

exec bash, or, more robustly, exec "$BASH"[1], will replace your current shell with a new instance, and therefore only preserve your current shell's environment variables (including ones you've defined ad hoc, in-session). In other words: Any ad-hoc changes to the current shell in terms of shell variables, shell functions, shell options, command history are lost.

In other words: Any ad-hoc changes to the current shell in terms of shell variables, shell functions, shell options, command history are lost.

Depending on your needs, one or the other approach may be preferred.

Note: The above applies analogously to other shells too:

To apply the exec approach to whatever your default shell is, use exec $SHELL

Similarly, the sourcing approach requires you to know and specify the name of the shell-specific initialization file; e.g., for zsh: . ~/.zshrc

^{[1] exec bash could in theory execute a different bash executable than the one that started the current shell, if it happens to exist in a directory listed earlier in the $PATH. Since special variable $BASH always contains the full path of the executable that started the current shell, exec "$BASH" is guaranteed to use the same executable.
A note re "..." around $BASH: double-quoting ensures that the variable value is used as-is, without interpretation by Bash; if the value has no embedded spaces or other shell metacharacters (which is likely in this case), you don't strictly need double quotes, but using them is a good habit to form.}

Someone edited my answer to add incorrect English, but here was the original, which is inferior to the accepted answer.

. .bashrc

With this, you won't even have to type "source ~/.bashrc":

Include your bashrc file:

alias rc="vim ~/.bashrc && source ~/.bashrc"

Every time you want to edit your bashrc, just run the alias "rc"

Depending on your environment, just typing

bash

may also work.

. ~/.bashrc

. is a POSIX-mandated builtin

Alternatives

source ~/.bashrc

source is a synonym for dot/period . in bash, but not in POSIX sh, so for maximum compatibility use the period.

exec bash

exec command replaces the shell with a given program... – WhoSayIn

exec bash is a great way to re-execute and launch a new shell to replace current. just to add to the answer, $SHELL returns the current shell which is bash. By using the following, it will reload the current shell, and not only to bash.

exec $SHELL -l;

I used easyengine to set up my vultr cloud based server.
I found my bash file at /etc/bash.bashrc.

So source /etc/bash.bashrc did the trick for me!

update

When setting up a bare server (ubuntu 16.04), you can use the above info, when you have not yet set up a username, and are logging in via root.

It's best to create a user (with sudo privileges), and login as this username instead.
This will create a directory for your settings, including .profile and .bashrc files as described on the previous ressource.

Now, you will edit and (and source) the ~/.bashrc file.

On my server, this was located at /home/your_username/.bashrc
(where your_username is actually the new username you created above, and now login with)

Depending upon your environment, you may want to add scripting to have .bashrc load automatically when you open an SSH session. I recently did a migration to a server running Ubuntu, and there, .profile, not .bashrc or .bash_profile is loaded by default. To run any scripts in .bashrc, I had to run source ~/.bashrc every time a session was opened, which doesn't help when running remote deploys.

To have your .bashrc load automatically when opening a session, try adding this to .profile:

if [ -n "$BASH_VERSION" ]; then
    # include .bashrc if it exists
    if [ -f "$HOME/.bashrc" ]; then
        . "$HOME/.bashrc"
    fi
fi

Reopen your session, and it should load any paths/scripts you have in .bashrc.

For me what works when I change the PATH is: exec "$BASH" --login

i use the following command on msysgit

. ~/.bashrc

shorter version of

source ~/.bashrc

Assuming an interactive shell, and you'd like to keep your current command history and also load /etc/profile (which loads environment data including /etc/bashrc and on Mac OS X loads paths defined in /etc/paths.d/ via path_helper), append your command history and do an exec of bash with the login ('-l') option:

history -a && exec bash -l

I noticed that pure exec bash command will preserve the environment variables, so you need to use exec -c bash to run bash in an empty environment.

For example, you login a bash, and export A=1, if you exec bash, the A == 1.

If you exec -cl bash, A is empty.

I think this is the best way to do your job.

I understand you want a shell as after logging out and in again. I believe the best way to achieve that is:

exec env -i HOME="$HOME" "$SHELL" -l

exec will replace the current shell, such that you are not left with it when the new one exits. env will create a new empty environment, with -i we add $HOME so that your shell (usually bash) given by $SHELL can find ~/.profile/~/.bash_profile (and thus (on ubuntu or if specified) ~/.bashrc). Those will be sourced thanks to -l. I'm not completely sure though.

This will also work..

cd ~
source .bashrc

I wrote a set of scripts I called bash_magic that automates this process across numerous shells. If you update a shell file in the bash magic shell directory (.bash.d by default), it will automatically source the update at the next prompt. So once you've made a change, just hit the Enter/return key and any updates will be sourced.