Fish Shell:
Writing to standard error

How to:

In Fish Shell, you can write to stderr by redirecting your output using >&2. Here is a basic example:

echo "This is an error message" >&2

This command simply echoes a message to stderr instead of stdout. If you were to write a script that outputs both regular and error messages, you might do something like this:

echo "Starting the process"
echo "An error occurred" >&2
echo "Process completed"

Sample output if you run the script and redirect stderr to a file:

Starting the process
Process completed

The error message would not appear in the standard output but would be found in the file you redirected stderr to.

In scenarios requiring more sophisticated error handling or logging, Fish doesn’t come with built-in libraries explicitly designed for this. However, you can leverage external tools or write functions to assist. For example, creating a simple logging function might look like this:

function log_error
    echo $argv >&2
end

log_error "This is an advanced error message"

This function log_error will take any string you give it and write it to stderr. Using functions like this can help keep your error handling clean and consistent throughout your scripts.