Include common functions in multiple bash scripts

Question

Using Ubuntu 18.04. My .bashrc file includes the lines:

if [ -f ~/.bash_usr_functions ]; then
    . ~/.bash_usr_functions
fi

In .bash_usr_functions, there are a bunch of user-defined functions such as:

function MyAmazingFunc()
{
    echo 1st param: $1
    echo Function body is complex...omitted for brevity
}

Now whenever a new Linux Terminal is started, typing MyAmazingFunc 37 works as expected. Great!

Now I write a new bash script. This script would like to know about and use AmazingFunc. I had expected this to be automatic with this code:

#!/bin/bash
AmazingFunc 37

but when I run this using bash ./NewScript.sh there is an error: Command 'MyAmazingFunc' not found.

So, I modified NewScript.sh to include the same lines from .bashrc:

if [ -f ~/.bash_usr_functions ]; then
    . ~/.bash_usr_functions
fi

This appears to work, but is very inelegant. Sourcing .bash_usr_functions actually launches a new, child bash process and runs any code in .bash_usr_functions! This can be verified by putting something like echo Hello from user functions or read VAR1 in that file.

Is there a better method to include your own user functions in a codebase (ie. many scripts) without having to copy the entire function into every bash script or use source?

Sourcing does not launch a child process. It reads the sourced file in the current shell process. — John Kugelman
– John Kugelman, Commented Nov 2, 2019 at 1:27

Cyrus · Accepted Answer · 2019-11-01 17:56:02Z

3

Add this to your ~/.bashrc to export your function to the environment of subsequently executed commands:

export -f MyAmazingFunc

See: help export

answered Nov 1, 2019 at 17:56

Cyrus

90.2k15 gold badges112 silver badges173 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

AlainD Over a year ago

Great, that works. Added it to the .bash_usr_functions file (just below the definition of MyAmazingFunc).

dash-o · Accepted Answer · 2019-11-02 01:22:51Z

1

Note that '.bashrc' is only executed for 'interactive shell' - login shell, or when using (-i). If you want to be able to run your 'NewScript.sh' in other context, consider alternative implementing using 'include guard'. This will remove the dependency on the login shell.

In NewScript.sh

[ "$user_functions_loaded" ] || source ~/.bash_usr_functions

In ~/.bash_usr_functions

user_functions_loaded=1
func AmazingFunc ...

This approach eliminate the need to export individual functions - recall that if 'MyAmazingFunc' is calling other functions in ~/.bash_usr_functions, those will also have to be exported

answered Nov 2, 2019 at 1:22

dash-o

14.6k1 gold badge14 silver badges43 bronze badges

Comments

ctac_ · Accepted Answer · 2019-11-02 18:00:00Z

0

Perhaps you can use BASH_ENV!
Try to add this line in your .xsessionrc file.

export BASH_ENV="$HOME/.bash_usr_functions"

answered Nov 2, 2019 at 18:00

ctac_

2,5012 gold badges10 silver badges18 bronze badges

Collectives™ on Stack Overflow

Include common functions in multiple bash scripts

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related