Shell Programming and Scripting

echo "setup.001"|sed 's/.0/.r/g'

for file in setup.* ; do mv $file `echo $file | sed 's/.0/.r/g'` ; done

echo "setup.010"|sed 's/.0/.r/g'

rename s/\.[0-9]/.r/ *

sed 's/.0/.r/'

#!/bin/ksh
# or bash

# split filename using dot to the two variable
ls setup.* | while IFS="." read start end 
do

        oldname="$start.$end"
        # substring starting from second char and give length nothing = rest of data
        end="r${end:1}"
        newname="$start.$end"
        [ "$newname" = "$oldname" ] && continue
        # remove echo if looks good
        echo mv "$oldname" "$newname"
done