Date: 2016may1 Language: bash Q. bash: How can I change uppercase to lowercase in a bash script. A. If you have bash4+

myvar="${myvar,,}"

Otherwise, use the tr (translate) command:

tr '[:upper:]' '[:lower:]' <filein >fileout

The older style (that still works):

tr '[A-Z]' '[a-z]' <filein >fileout

This is slightly shorted but not quite as clear. To make the contents of a bash variable lowercase:

myvar=$(echo $myvar | tr '[:upper:]' '[:lower:]')