A simple bash function to test existence of required programs

check-pre-reqs.sh

#!/bin/bash
#
# Simple bash function to test existence of required programs for script
# to work properly. Utilizes bash array
#
function check_pre_reqs {
  declare -a procrams=($*)

  for item in ${procrams[*]}; do
    if test "$(type -p $item)" == ""; then
      proc_names="$proc_names $item"
    fi
  done

  if test "$proc_names" != ""; then
    echo "Script requires following programs to work:$proc_names"
    exit 1
  fi
}

check_pre_reqs "awk" "cabextract" "fooz" "git" "ilspycmd" "msiextract" "xmllint"