The Jez McKinley Wiki

Change files in directory from upper to lower case :

ls *.JPG | awk ' { print $1" "tolower($1) } ' | xargs -t -n2 mv

or :

find ./* -name "*.JPG" | awk ' { print $1" "tolower($1) } ' | xargs -t -n2 mv

Change case of words inside files :

cat welcomech.htm | sed s/".HTM"/.htm/ > tmp.htm && cp tmp.htm welcomech.htm