I would like to add to more test elements 1. there must be at least one Upper Case character 2. there are no no single one character space separated items examples: 1=hello world = bad 1=Hello w = bad 1=Hello World = good if [[ $1 = *\ * ]] && [[ ! $1 = *@* ]] && [[ ! $1 = *=* ]] then echo 1 fi