UNIX for Dummies Questions & Answers

Hi Unix Gurus,

I would like to rename several files in a Unix Directory . The filenames can have more than 1 underscore ( _ ) and the last underscore is always followed by a date in the format mmddyyyy. The Extension of the files can be .txt or .pdf or .xls etc and is case insensitive ie .Xls or .XLS is also possible. Now i need to convert such a file to date format which ends with yyyymmdd.

For eg E-SSS_Reporting_for_Small_Groups_10012013.xls needs to be renamed as E-SSS_Reporting_for_Small_Groups_20131001.xls

How can i accomplish this?

Appreciate your Help on this.

Code:

DIR=/your/directory
for FILE in $(ls $DIR)
do
 OLD_DT=$(echo ${FILE##*_} | cut -d. -f 1)
 NEW_DT=$(expr substr $OLD_DT 5 4)$(expr substr $OLD_DT 1 4)
 RENAMED_FILE=$(echo ${FILE%_*})"_"${NEW_DT}"."$(echo ${FILE##*.})
 echo mv $DIR/$FILE $DIR/$RENAMED_FILE
done

Replace the red marked /your/directory with the directory name where you have the files.

After reviewing the output you may remove the red echo and execute for renaming files.