sudo bash -c "source loadmyscript && myscriptfn '$@'" _ "$@" this doesn't work

When attempting to run the command sudo bash -c "source loadmyscript && myscriptfn '$@'" _ "$@", you may encounter issues due to the nature of the source command in shell environments. Understanding the context and the limitations of running such commands with sudo is crucial. Here’s a detailed breakdown of the problem, along with solutions to help you troubleshoot.

Understanding the Problem

The Nature of source

The source command is a builtin command in shell environments, particularly in Bash. Its primary role is to execute commands from a file in the current shell context. However, when you run it with sudo, the command is executed in a different shell instance initiated by bash -c, where source is not recognized because it is not a standalone executable.

Common Errors

When you run your command, you may encounter an error like:

sudo: source: command not found

This is because sudo is trying to execute source as if it were a separate program, which it is not.

Solutions and Workarounds

1. Use the . Command

Instead of using source, you can use the . (dot) command, which functions identically and is recognized by sudo as an executable command:

sudo bash -c ". loadmyscript && myscriptfn '$@'" _ "$@"

2. Execute the Script as Root

If your script requires higher privileges, consider running the entire script directly with sudo without sourcing it:

sudo bash -c "myscriptfn <(loadmyscript)"

In this command, you'll need to ensure that loadmyscript can act as a setup for myscriptfn.

3. Change to a Login Shell

Another alternative is to change your command by invoking a login shell:

sudo bash -l -c "source loadmyscript && myscriptfn '$@'" _ "$@"

This method uses the -l option which starts a login shell, allowing access to environment variables and settings defined in login profiles.

4. Create a Wrapper Script

If you find that myscriptfn frequently requires the environment setup by loadmyscript, consider wrapping the two commands in a separate shell script. Create a script (e.g., runmyscript.sh) like this:

#!/bin/bash
source loadmyscript
myscriptfn "$@"

Make this script executable and run it with sudo:

sudo ./runmyscript.sh "$@"

Conclusion

The issues you encounter with the command sudo bash -c "source loadmyscript && myscriptfn '$@'" _ "$@" arise from the nature of built-in shell commands not being recognized by sudo. By employing alternatives such as substituting source with the . command or creating a wrapper script, you can effectively troubleshoot and resolve any issues.

Whenever faced with similar problems, remember that understanding the underlying command nature often provides the quickest path to a solution. Always refer to shell documentation or community resources for more complex scenarios and in-depth troubleshooting.