I need a script to change the case of file extensions from upper to lower case. I don't think I can do it just in the ordinary bash shell, and I know nothing about awk

#!/bin/ksh if [[ $# != 1 ]] then echo "Usage: $0 filename" exit fi echo $1 | cut -d. -f1 | read PREFIX echo $1 | cut -d. -f2 | read SUFFIX echo $SUFFIX | tr "[:upper:]" "[:lower:]" | read suffix echo $PREFIX.$suffix

The solution above would fail on a filename like: my.test.TXT korn shell has built-in functions that make this easy and efficient, and avoids all the piped processes. typeset -l will force to lowercase. After testing, remove the echo to enable the mv command. #!/bin/ksh if [ $# -ne 1 ] ; then    echo "Usage: $0 filename"    exit fi typeset -l SUFFIX PREFIX=${1%.*} SUFFIX=${1#$PREFIX} echo mv -i $1 $PREFIX$SUFFIX exit 0

Rao: This cunstruction may work, but often fails: echo $1 | cut -d. -f1 | read PREFIX more is here: http://www.tldp.org/LDP/abs/html/gotchas.html#BADREAD0