Uppercased command aliasing in bash script?

Question

I have a script I'm trying to make at least somewhat platform-independent. Because I can't count on the PATHs or shell aliases of my users (some of whom have been known to create aliases matching "reserved words" meaningful to the shell), I've taken to aliasing all non-builtin shell commands with uppercase equivalents. This works fine when I do it semi-manually, e.g.

AWK=/usr/bin/awk
DATE=/bin/date
GREP=/bin/grep

, but not so well when I try it in a function by iterating through an array of commands:

createAliases() {
    COMMANDS=(awk chmod date echo git mkdir)
    WHICH=/usr/bin/which

    for command in ${COMMANDS[@]}; do
        ${command^^}=$($WHICH ${command})
    done
}

, which produces errors like AWK=/usr/bin/awk: No such file or directory. Is my attempt to use the string^^ up-casing mechanism interfering with the variable assignment? It looks like the shell is actually trying to run the (aliased) commands, which is not what I want.

Any assistance is appreciated!

Answer 1

The following seems to work:

shopt -s expand_aliases
createAliases() {
    COMMANDS=(awk chmod date echo git mkdir)
    WHICH=/usr/bin/which

    for command in ${COMMANDS[@]}; do
        alias ${command^^}=$($WHICH ${command})
    done
}

Prefixing the assigment with alias actually registers the desired aliases.

The line shopt -s expand_aliases enables you to then use these alias from anywhere in the script, according to https://www.thegeekdiary.com/how-to-make-alias-command-work-in-bash-script-or-bashrc-file/