Can not successfully source .bashrc from a shell script

Question

Normally we can source ~/.bashrc file using this command

source ~/.bashrc

but if I write this in a shell script and execute it, nothing happen. Why?
Is there any way to do this?

my shell code:

#!/bin/bash
chmod a+x ~/.bashrc
source ~/.bashrc

Also tried .[dot] instead of source. Same result

Answer 1

A shell script is run in its own shell instance. All the variable settings, function definitions and such only affect this instance (and maybe its children) but not the calling shell so they are gone after the script finished.

By contrast the source command doesn't start a new shell instance but uses the current shell so the changes remain.

If you want a shortcut to read your .bashrc use a shell function or an alias instead of a shell script, like

alias brc='source ~/.bashrc'

Answer 2

Your .bashrc usually starts:

# If not running interactively, don't do anything
[ -z "$PS1" ] && return

Since your script does not have PS1 set (because it is not interactive), it doesn't reset path because it exits early . To demonstrate, modify your script:

    #!/bin/bash
    chmod a+x ~/.bashrc
    PS1='$ '
    source ~/.bashrc

this will now allow your scripts to work with the new .bashrc. Note: once your script exits , the env will be set to what it was before starting the script . The changes will be reflected the next time a terminal is started.

Answer 3

Try:

exec bash

This should reload ~/.bashrc, ~/.bash_aliases, etc.