Bash – Implementing dry-run in bash scripts

bash

How would one implement a dry-run option in a bash script?

I can think of either wrapping every single command in an if and echoing out the command instead of running it if the script is running with dry-run.

Another way would be to define a function and then passing each command call through that function.

Something like:

function _run () {
    if [[ "$DRY_RUN" ]]; then
        echo $@
    else
        $@
    fi
}

`_run mv /tmp/file /tmp/file2`

`DRY_RUN=true _run mv /tmp/file /tmp/file2`

Is this just wrong and there is a much better way of doing it?

Best Answer

See BashFAQ/050: I'm trying to put a command in a variable, but the complex cases always fail! for a discussion of this subject.

Although now removed, the section How to add testing capability to a programs may still be useful.

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