Command decoration along the $PATH

example

#!/bin/bash
# an hypothetical /usr/local/bin/example intercepts invocations to /usr/bin/example

export SPECIAL_VAR="customize enviroments for all invocations"

do_something_before

# now invoke the same command somewhere down the $PATH (e.g. /usr/bin/example), 
unwrap "$0" "${@}" --add-an-option

do_something_after # if not necessary use "exec" in the previous command

unwrap

#!/bin/bash -euf

function unwrap {
    export PATH="$(echo "$PATH" | sed -e "s:$(dirname "$(which "$1")")\:::" )" \
        which "$(basename $1)" 2>/dev/null
}

function main {
    if [ -z "$@" ]; then
        echo "Usage: $0 <command> [<args>]"
        exit 1
    fi
    local cmd="$(unwrap "$1" || (
        echo "WARNING: '$1' is not wrapped" >&2
        echo "$1"
    ))"
    exec "$cmd" "${@:2}"
}

main "$@"