Is it possible to move variables above those upon which they depend?

I want to keep the configuration variables at the very top, but they depend upon other variables which need to be above them. How can I (if that's possible) move a don't touch section below a config section?

To illustrate:

#!/bin/bash

#== don't touch ==
 dirpath=$(dirname "$1")
 dirname=$(basename $(dirname "$1"))

#== config ==
 path="$dirpath"   #using the value of $dirpath straight in config would be ugly.
 name="$dirname" 

 echo "$path" + "$name"

..but I want to move the config above everything else:

#!/bin/bash

#== config ==
开发者_Python百科 path="$dirpath"   #using the value of $dirpath straight in config would be ugly.
 name="$dirname" 

#== don't touch ==  
 dirpath=$(dirname "$1")
 dirname=$(basename $(dirname "$1"))

 echo "$path" + "$name"

Update

The usual pattern is:

#!/bin/bash
function main()
{ 
    prepare
    do_step1 args ...
    do_step2 args ...
    do_step3 args ...
    do_step4 args ...

    exit 0
}

function prepare() { .... }
function do_step1() { ....}
function do_step2() { ....}
function do_step3() { ....}
function do_step4() { ....}

// entry point
main

As long as the (sub)function definitions precede invocation, they will be found nicely.

Literal answers:

No, you'd need to have functions for that, or you eval:

export dynamic="interesting"
function getsomething() { echo -n "$dynamic"; }

export dynamic="stuff"
echo "$(getsomething)"

will display "stuff", not "interesting"

The eval approach:

export param=value1
export dependent='$param' # (note the SINGLE quotes)

export param=value2
eval "echo $dependent"

will print, "value2", not "value1"

Cosmetics:

If it's just about don't touch source an include file:

  source donot_touch.sh