=word}
If varname exists and isn't null, return its value; otherwise set it to word and then return its value.[7]
Purpose:
Setting a variable to a de... ssage}
If varname exists and isn't null, return its value; otherwise print varname: followed by messa... efficient than ${variable##/*} because it runs in its own separate process rather than within the shell... nts to p and d so that we skip the root directory itself -- which must be "special cased" since it appe
