Changing file extension ..

Question

i have a files like *.aaa
*.aaa
*.bbb
*.bbb
*.ccc
*.ccc
*.ccc
*.ddd
*.ddd
like this i 've to write a scripte to convert *.aaa files to .a,*.bbb files to .b,*.ccc files to .c and any rather than this files convert to *.txt

Answer 1

Perhaps the following shells script will do the job:
<pre>
for file in *; do
case $file in
*.aaa) mv $file ${file%.*}.a ;;
*.bbb) mv $file ${file%.*}.b ;;
*.ccc) mv $file ${file%.*}.c ;;
*) mv $file ${file%.*}.txt ;;
esac
done
</pre>