OpenWritings.net

#!/bin/bash
 
# Description: Get filenme without extension.
# Author: Xuan Ngo
#############################################
 
filename=my_filename.txt
echo ${filename}
 
# Length of .txt is equal to 4
let fileLength=${#filename}-4
filenameWithNoExt=${filename:0:${fileLength}}
 
echo ${filenameWithNoExt} 
 
# Output:
#  my_filename.txt
#  my_filename

# http://tldp.org/LDP/GNU-Linux-Tools-Summary/html/mass-rename.html
for i in *.JPG; 
do mv $i `basename $i JPG`jpg; 
done 
 
# or
for i in *.JPG; 
do mv $i ${i%%.JPG}.jpg; 
done